diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9806861d..c3bff28b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,10 @@
+## 1.1.0
+- Updated to send datafile revision information in log events.
+- Gracefully handle empty entity IDs.
+- Added event tags to track API to allow users to pass in event metadata.
+- Deprecated the `eventValue` parameter from the track method. Should use `eventTags` to pass in event value instead.
+- Relaxed restriction on monolog package. 
+
 ## 1.0.1
 - Updated to support more versions of json-schema package.
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 9525e100..ca26a035 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,7 +1,7 @@
-#Contributing to the Optimizely PHP SDK
+# Contributing to the Optimizely PHP SDK
 We welcome contributions and feedback! All contributors must sign our [Contributor License Agreement (CLA)](https://docs.google.com/a/optimizely.com/forms/d/e/1FAIpQLSf9cbouWptIpMgukAKZZOIAhafvjFCV8hS00XJLWQnWDFtwtA/viewform) to be eligible to contribute. Please read the [README](README.md) to set up your development environment, then read the guidelines below for information on submitting your code.
 
-##Development process
+## Development process
 
 1. Create a branch off of `devel`: `git checkout -b YOUR_NAME/branch_name`.
 2. Commit your changes. Make sure to add tests!
@@ -10,12 +10,12 @@ We welcome contributions and feedback! All contributors must sign our [Contribut
 5. Open a pull request from `YOUR_NAME/branch_name` to `devel`.
 6. A repository maintainer will review your pull request and, if all goes well, merge it!
 
-##Pull request acceptance criteria
+## Pull request acceptance criteria
 
 * **All code must have test coverage.** We use PHPUnit. Changes in functionality should have accompanying unit tests. Bug fixes should have accompanying regression tests.
 * Tests are located in `tests` with one file per class.
 
-##License
+## License
 
 All contributions are under the CLA mentioned above. For this project, Optimizely uses the Apache 2.0 license, and so asks that by contributing your code, you agree to license your contribution under the terms of the [Apache License v2.0](http://www.apache.org/licenses/LICENSE-2.0). Your contributions should also include the following header:
 
@@ -39,5 +39,5 @@ All contributions are under the CLA mentioned above. For this project, Optimizel
 
 The YEAR above should be the year of the contribution. If work on the file has been done over multiple years, list each year in the section above. Example: Optimizely writes the file and releases it in 2014. No changes are made in 2015. Change made in 2016. YEAR should be “2014, 2016”.
 
-##Contact
+## Contact
 If you have questions, please contact developers@optimizely.com.
diff --git a/README.md b/README.md
index ad07d982..ff3e206d 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-#Optimizely PHP SDK
+# Optimizely PHP SDK
 [![Build Status](https://travis-ci.org/optimizely/php-sdk.svg?branch=master)](https://travis-ci.org/optimizely/php-sdk)
 [![Coverage Status](https://coveralls.io/repos/github/optimizely/php-sdk/badge.svg?branch=master)](https://coveralls.io/github/optimizely/php-sdk?branch=master)
 [![Total Downloads](https://poser.pugx.org/optimizely/optimizely-sdk/downloads)](https://packagist.org/packages/optimizely/optimizely-sdk)
@@ -6,9 +6,9 @@
 
 This repository houses the PHP SDK for Optimizely Full Stack.
 
-##Getting Started
+## Getting Started
 
-###Installing the SDK
+### Installing the SDK
 
 The Optimizely PHP SDK can be installed through [Composer](https://getcomposer.org/). Please use the following command: 
 
@@ -16,20 +16,20 @@ The Optimizely PHP SDK can be installed through [Composer](https://getcomposer.o
 php composer.phar require optimizely/optimizely-sdk
 ```
 
-###Using the SDK
+### Using the SDK
 See the Optimizely Full Stack [developer documentation](https://developers.optimizely.com/x/solutions/sdks/reference/?language=php) to learn how to set up your first Full Stack project and use the SDK.
 
-##Development
+## Development
 
-###Unit tests
+### Unit tests
 
-#####Running all tests
+##### Running all tests
 You can run all unit tests with:
 
 ```
 ./vendor/bin/phpunit
 ```
 
-###Contributing
+### Contributing
 
 Please see [CONTRIBUTING](CONTRIBUTING.md).
diff --git a/composer.json b/composer.json
index 77500a73..863daa63 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
     "justinrainbow/json-schema": "^1.6 || ^2.0 || ^4.0",
     "lastguest/murmurhash": "1.3.0",
     "guzzlehttp/guzzle": "~5.3|~6.2",
-    "monolog/monolog": "1.21.0"
+    "monolog/monolog": "~1.21"
   },
   "require-dev": {
     "phpunit/phpunit": "~4.8|~5.0",
diff --git a/src/Optimizely/Bucketer.php b/src/Optimizely/Bucketer.php
index 3e94d116..03119c39 100644
--- a/src/Optimizely/Bucketer.php
+++ b/src/Optimizely/Bucketer.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Copyright 2016, Optimizely
+ * Copyright 2016-2017, Optimizely
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -92,7 +92,7 @@ protected function generateBucketValue($bucketingId)
      * @param $parentId mixed ID representing Experiment or Group.
      * @param $trafficAllocations array Traffic allocations for variation or experiment.
      *
-     * @returns string ID representing experiment or variation.
+     * @return string ID representing experiment or variation.
      */
     private function findBucket($userId, $parentId, $trafficAllocations)
     {
@@ -150,7 +150,7 @@ public function bucket(ProjectConfig $config, Experiment $experiment, $userId)
             }
 
             $userExperimentId = $this->findBucket($userId, $group->getId(), $group->getTrafficAllocation());
-            if (is_null($userExperimentId)) {
+            if (empty($userExperimentId)) {
                 $this->_logger->log(Logger::INFO, sprintf('User "%s" is in no experiment.', $userId));
                 return new Variation();
             }
@@ -172,7 +172,7 @@ public function bucket(ProjectConfig $config, Experiment $experiment, $userId)
 
         // Bucket user if not in whitelist and in group (if any).
         $variationId = $this->findBucket($userId, $experiment->getId(), $experiment->getTrafficAllocation());
-        if (!is_null($variationId)) {
+        if (!empty($variationId)) {
             $variation = $config->getVariationFromId($experiment->getKey(), $variationId);
             $this->_logger->log(Logger::INFO,
                 sprintf('User "%s" is in variation %s of experiment %s.',
diff --git a/src/Optimizely/Event/Builder/EventBuilder.php b/src/Optimizely/Event/Builder/EventBuilder.php
index 3e626c04..6f2f7a98 100644
--- a/src/Optimizely/Event/Builder/EventBuilder.php
+++ b/src/Optimizely/Event/Builder/EventBuilder.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Copyright 2016, Optimizely
+ * Copyright 2016-2017, Optimizely
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@
 use Optimizely\Entity\Experiment;
 use Optimizely\Event\LogEvent;
 use Optimizely\ProjectConfig;
+use Optimizely\Utils\EventTagUtils;
 
 class EventBuilder
 {
@@ -33,7 +34,7 @@ class EventBuilder
     /**
      * @const string Version of the Optimizely PHP SDK.
      */
-    const SDK_VERSION = '1.0.1';
+    const SDK_VERSION = '1.1.0';
 
     /**
      * @var string URL to send impression event to.
@@ -104,6 +105,7 @@ private function setCommonParams($config, $userId, $attributes)
     {
         $this->_eventParams[PROJECT_ID] = $config->getProjectId();
         $this->_eventParams[ACCOUNT_ID] = $config->getAccountId();
+        $this->_eventParams[REVISION] = $config->getRevision();
         $this->_eventParams[VISITOR_ID] = $userId;
         $this->_eventParams[CLIENT_ENGINE] = self::SDK_TYPE;
         $this->_eventParams[CLIENT_VERSION] = self::SDK_VERSION;
@@ -153,20 +155,34 @@ private function setImpressionParams(Experiment $experiment, $variationId)
      * @param $eventKey string Key representing the event.
      * @param $experiments array Experiments for which conversion event needs to be recorded.
      * @param $userId string ID of user.
-     * @param $eventValue integer Value associated with the event.
+     * @param $eventTags array Hash representing metadata associated with the event.
      */
-    private function setConversionParams($config, $eventKey, $experiments, $userId, $eventValue)
+    private function setConversionParams($config, $eventKey, $experiments, $userId, $eventTags)
     {
         $this->_eventParams[EVENT_FEATURES] = [];
         $this->_eventParams[EVENT_METRICS] = [];
 
-        if (!is_null($eventValue)) {
-            $this->_eventParams[EVENT_METRICS] = [
-                [
-                    'name' => 'revenue',
-                    'value' => $eventValue
-                ]
-            ];
+        if (!is_null($eventTags)) {
+            forEach ($eventTags as $eventTagId => $eventTagValue) {
+                if (is_null($eventTagValue)) {
+                    continue;
+                }
+                $eventFeature = array(
+                    'name' => $eventTagId,
+                    'type' => 'custom',
+                    'value' => $eventTagValue,
+                    'shouldIndex' => false,
+                );
+                array_push($this->_eventParams[EVENT_FEATURES], $eventFeature);
+            }
+            $eventValue = EventTagUtils::getRevenueValue($eventTags);
+            if ($eventValue) {
+                $eventMetric = array(
+                    'name' => EventTagUtils::REVENUE_EVENT_METRIC_NAME,
+                    'value' => $eventValue,
+                );
+                array_push($this->_eventParams[EVENT_METRICS], $eventMetric);
+            }
         }
 
         $eventEntity = $config->getEvent($eventKey);
@@ -180,6 +196,7 @@ private function setConversionParams($config, $eventKey, $experiments, $userId,
                 array_push($this->_eventParams[LAYER_STATES], [
                     LAYER_ID => $experiment->getLayerId(),
                     ACTION_TRIGGERED => true,
+                    REVISION => $config->getRevision(),
                     DECISION => [
                         EXPERIMENT_ID => $experiment->getId(),
                         VARIATION_ID => $variation->getId(),
@@ -218,15 +235,15 @@ public function createImpressionEvent($config, Experiment $experiment, $variatio
      * @param $experiments array Experiments for which conversion event needs to be recorded.
      * @param $userId string ID of user.
      * @param $attributes array Attributes of the user.
-     * @param $eventValue integer Value associated with the event.
+     * @param $eventTags array Hash representing metadata associated with the event.
      *
      * @return LogEvent Event object to be sent to dispatcher.
      */
-    public function createConversionEvent($config, $eventKey, $experiments, $userId, $attributes, $eventValue)
+    public function createConversionEvent($config, $eventKey, $experiments, $userId, $attributes, $eventTags)
     {
         $this->resetParams();
         $this->setCommonParams($config, $userId, $attributes);
-        $this->setConversionParams($config, $eventKey, $experiments, $userId, $eventValue);
+        $this->setConversionParams($config, $eventKey, $experiments, $userId, $eventTags);
 
         return new LogEvent(self::$CONVERSION_ENDPOINT, $this->getParams(), self::$HTTP_VERB, self::$HTTP_HEADERS);
     }
diff --git a/src/Optimizely/Event/Builder/Params.php b/src/Optimizely/Event/Builder/Params.php
index d2baa635..4779adcd 100644
--- a/src/Optimizely/Event/Builder/Params.php
+++ b/src/Optimizely/Event/Builder/Params.php
@@ -17,6 +17,7 @@
 
 define('ACCOUNT_ID', 'accountId');
 define('PROJECT_ID', 'projectId');
+define('REVISION', 'revision');
 define('LAYER_ID', 'layerId');
 define('EXPERIMENT_ID', 'experimentId');
 define('VARIATION_ID', 'variationId');
diff --git a/src/Optimizely/Exceptions/InvalidEventTagException.php b/src/Optimizely/Exceptions/InvalidEventTagException.php
new file mode 100644
index 00000000..195c7a90
--- /dev/null
+++ b/src/Optimizely/Exceptions/InvalidEventTagException.php
@@ -0,0 +1,23 @@
+<?php
+/**
+ * Copyright 2017, Optimizely
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Optimizely\Exceptions;
+
+
+class InvalidEventTagException extends OptimizelyException
+{
+}
diff --git a/src/Optimizely/Optimizely.php b/src/Optimizely/Optimizely.php
index ffc3a640..245da822 100644
--- a/src/Optimizely/Optimizely.php
+++ b/src/Optimizely/Optimizely.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Copyright 2016, Optimizely
+ * Copyright 2016-2017, Optimizely
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@
 
 use Exception;
 use Optimizely\Exceptions\InvalidAttributeException;
+use Optimizely\Exceptions\InvalidEventTagException;
 use Throwable;
 use Monolog\Logger;
 use Optimizely\Entity\Experiment;
@@ -29,6 +30,7 @@
 use Optimizely\Event\Dispatcher\EventDispatcherInterface;
 use Optimizely\Logger\LoggerInterface;
 use Optimizely\Logger\NoOpLogger;
+use Optimizely\Utils\EventTagUtils;
 use Optimizely\Utils\Validator;
 
 /**
@@ -240,9 +242,9 @@ public function activate($experimentKey, $userId, $attributes = null)
      * @param $eventKey string Event key representing the event which needs to be recorded.
      * @param $userId string ID for user.
      * @param $attributes array Attributes of the user.
-     * @param $eventValue integer Value associated with event.
+     * @param $eventTags array Hash representing metadata associated with the event.
      */
-    public function track($eventKey, $userId, $attributes = null, $eventValue = null)
+    public function track($eventKey, $userId, $attributes = null, $eventTags = null)
     {
         if (!$this->_isValid) {
             $this->_logger->log(Logger::ERROR, 'Datafile has invalid format. Failing "track".');
@@ -257,6 +259,24 @@ public function track($eventKey, $userId, $attributes = null, $eventValue = null
             return;
         }
 
+        if (!is_null($eventTags)) {
+            if (is_numeric($eventTags) && !is_string($eventTags)) {
+                $eventTags = array(
+                    EventTagUtils::REVENUE_EVENT_METRIC_NAME => $eventTags,
+                );
+                $this->_logger->log(
+                    Logger::WARNING,
+                    'Event value is deprecated in track call. Use event tags to pass in revenue value instead.'
+                );
+            }
+            if (!Validator::areEventTagsValid($eventTags)) {
+                $this->_logger->log(Logger::ERROR, 'Provided event tags are in an invalid format.');
+                $this->_errorHandler->handleError(
+                    new InvalidEventTagException('Provided event tags are in an invalid format.')
+                );
+            }
+        }
+
         $event = $this->_config->getEvent($eventKey);
 
         if (is_null($event->getKey())) {
@@ -284,7 +304,7 @@ public function track($eventKey, $userId, $attributes = null, $eventValue = null
                     $validExperiments,
                     $userId,
                     $attributes,
-                    $eventValue
+                    $eventTags
                 );
             $this->_logger->log(Logger::INFO, sprintf('Tracking event "%s" for user "%s".', $eventKey, $userId));
             $this->_logger->log(
diff --git a/src/Optimizely/ProjectConfig.php b/src/Optimizely/ProjectConfig.php
index beed9a14..8a3f9216 100644
--- a/src/Optimizely/ProjectConfig.php
+++ b/src/Optimizely/ProjectConfig.php
@@ -184,6 +184,14 @@ public function getProjectId()
         return $this->_projectId;
     }
 
+    /**
+     * @return string String representing revision of the datafile.
+     */
+    public function getRevision()
+    {
+        return $this->_revision;
+    }
+
     /**
      * @param $groupId string ID of the group.
      *
diff --git a/src/Optimizely/Utils/EventTagUtils.php b/src/Optimizely/Utils/EventTagUtils.php
new file mode 100644
index 00000000..02b94196
--- /dev/null
+++ b/src/Optimizely/Utils/EventTagUtils.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * Copyright 2017, Optimizely
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Optimizely\Utils;
+
+class EventTagUtils
+{
+    /**
+     * @const string Reserved word for event tag representing event revenue value.
+     */
+    const REVENUE_EVENT_METRIC_NAME = 'revenue';
+
+    /**
+     * Grab the revenue value from the event tags. "revenue" is a reserved keyword.
+     *
+     * @param $eventTags array Representing metadata associated with the event.
+     * @return integer Revenue value as an integer number or null if revenue can't be retrieved from the event tags
+     */
+    public static function getRevenueValue($eventTags) {
+        if (!$eventTags) {
+            return null;
+        }
+        if (!is_array($eventTags)) {
+            return null;
+        }
+
+        if (!isset($eventTags[self::REVENUE_EVENT_METRIC_NAME]) or !$eventTags[self::REVENUE_EVENT_METRIC_NAME]) {
+            return null;
+        }
+
+        $raw_value = $eventTags[self::REVENUE_EVENT_METRIC_NAME];
+        if (!is_int($raw_value)) {
+            return null;
+        }
+
+        return $raw_value;
+    }
+}
diff --git a/src/Optimizely/Utils/Validator.php b/src/Optimizely/Utils/Validator.php
index 369336c3..ea7bf6a0 100644
--- a/src/Optimizely/Utils/Validator.php
+++ b/src/Optimizely/Utils/Validator.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Copyright 2016, Optimizely
+ * Copyright 2016-2017, Optimizely
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,7 +26,7 @@ class Validator
     /**
      * @param $datafile string JSON string representing the project.
      *
-     * @return boolean representing whether schema is valid or not.
+     * @return boolean Representing whether schema is valid or not.
      */
     public static function validateJsonSchema($datafile)
     {
@@ -41,13 +41,23 @@ public static function validateJsonSchema($datafile)
     /**
      * @param $attributes mixed Attributes of the user.
      *
-     * @return boolean representing whether attributes are valid or not.
+     * @return boolean Representing whether attributes are valid or not.
      */
     public static function areAttributesValid($attributes)
     {
         return is_array($attributes) && count(array_filter(array_keys($attributes), 'is_int')) == 0;
     }
 
+    /**
+     * @param $eventTags mixed Event tags to be validated.
+     *
+     * @return boolean Representing whether event tags are valid or not.
+     */
+    public static function areEventTagsValid($eventTags)
+    {
+        return is_array($eventTags) && count(array_filter(array_keys($eventTags), 'is_int')) == 0;
+    }
+
     /**
      * @param $config ProjectConfig Configuration for the project.
      * @param $experiment Experiment Entity representing the experiment.
diff --git a/tests/BucketerTest.php b/tests/BucketerTest.php
index 8f2a7338..a15b2940 100644
--- a/tests/BucketerTest.php
+++ b/tests/BucketerTest.php
@@ -82,11 +82,28 @@ public function testGenerateBucketValue()
     public function testBucketValidExperimentNotInGroup()
     {
         $bucketer = new TestBucketer($this->loggerMock);
-        $bucketer->setBucketValues([3000, 7000, 9000]);
+        $bucketer->setBucketValues([1000, 3000, 7000, 9000]);
         // Total calls in this test
-        $this->loggerMock->expects($this->exactly(6))
+        $this->loggerMock->expects($this->exactly(8))
             ->method('log');
 
+        // No variation (empty entity ID)
+        $this->loggerMock->expects($this->at(0))
+            ->method('log')
+            ->with(Logger::DEBUG, 'Assigned bucket 1000 to user "testUserId".');
+        $this->loggerMock->expects($this->at(1))
+            ->method('log')
+            ->with(Logger::INFO, 'User "testUserId" is in no variation.');
+
+        $this->assertEquals(
+            new Variation(),
+            $bucketer->bucket(
+                $this->config,
+                $this->config->getExperimentFromKey('test_experiment'),
+                $this->testUserId
+            )
+        );
+
         // control
         $this->loggerMock->expects($this->at(0))
             ->method('log')
@@ -145,10 +162,10 @@ public function testBucketValidExperimentInGroup()
     {
         $bucketer = new TestBucketer($this->loggerMock);
         // Total calls in this test
-        $this->loggerMock->expects($this->exactly(10))
+        $this->loggerMock->expects($this->exactly(14))
             ->method('log');
 
-        // group_experiment_1 (20% experiment)
+        // group_experiment_1 (15% experiment)
         // variation 1
         $bucketer->setBucketValues([1000, 4000]);
         $this->loggerMock->expects($this->at(0))
@@ -216,6 +233,41 @@ public function testBucketValidExperimentInGroup()
                 $this->testUserId
             )
         );
+
+        // User not in any experiment (previously allocated space)
+        $bucketer->setBucketValues([400]);
+        $this->loggerMock->expects($this->at(0))
+            ->method('log')
+            ->with(Logger::DEBUG, 'Assigned bucket 400 to user "testUserId".');
+        $this->loggerMock->expects($this->at(1))
+            ->method('log')
+            ->with(Logger::INFO, 'User "testUserId" is in no experiment.');
+
+        $this->assertEquals(
+            new Variation(),
+            $bucketer->bucket(
+                $this->config,
+                $this->config->getExperimentFromKey('group_experiment_1'),
+                $this->testUserId
+            )
+        );
+
+        // User not in any experiment (never allocated space)
+        $bucketer->setBucketValues([9000]);
+        $this->loggerMock->expects($this->at(0))
+            ->method('log')
+            ->with(Logger::DEBUG, 'Assigned bucket 9000 to user "testUserId".');
+        $this->loggerMock->expects($this->at(1))
+            ->method('log')
+            ->with(Logger::INFO, 'User "testUserId" is in no experiment.');
+        $this->assertEquals(
+            new Variation(),
+            $bucketer->bucket(
+                $this->config,
+                $this->config->getExperimentFromKey('group_experiment_1'),
+                $this->testUserId
+            )
+        );
     }
 
     public function testBucketInvalidExperiment()
diff --git a/tests/EventTests/EventBuilderTest.php b/tests/EventTests/EventBuilderTest.php
index c856160f..467c48eb 100644
--- a/tests/EventTests/EventBuilderTest.php
+++ b/tests/EventTests/EventBuilderTest.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Copyright 2016, Optimizely
+ * Copyright 2016-2017, Optimizely
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -45,10 +45,11 @@ public function testCreateImpressionEventNoAttributes()
             [
                 'projectId' => '7720880029',
                 'accountId' => '1592310167',
+                'revision' => '15',
                 'layerId' => '7719770039',
                 'visitorId' => 'testUserId',
                 'clientEngine' => 'php-sdk',
-                'clientVersion' => '1.0.1',
+                'clientVersion' => '1.1.0',
                 'timestamp' => time() * 1000,
                 'isGlobalHoldback' => false,
                 'userFeatures' => [],
@@ -79,10 +80,11 @@ public function testCreateImpressionEventWithAttributes()
             [
                 'projectId' => '7720880029',
                 'accountId' => '1592310167',
+                'revision' => '15',
                 'layerId' => '7719770039',
                 'visitorId' => 'testUserId',
                 'clientEngine' => 'php-sdk',
-                'clientVersion' => '1.0.1',
+                'clientVersion' => '1.1.0',
                 'timestamp' => time() * 1000,
                 'isGlobalHoldback' => false,
                 'userFeatures' => [[
@@ -125,8 +127,9 @@ public function testCreateConversionEventNoAttributesNoValue()
                 'projectId' => '7720880029',
                 'accountId' => '1592310167',
                 'visitorId' => 'testUserId',
+                'revision' => '15',
                 'clientEngine' => 'php-sdk',
-                'clientVersion' => '1.0.1',
+                'clientVersion' => '1.1.0',
                 'userFeatures' => [],
                 'isGlobalHoldback' => false,
                 'timestamp' => time() * 1000,
@@ -137,6 +140,7 @@ public function testCreateConversionEventNoAttributesNoValue()
                 'layerStates' => [[
                     'layerId' => '7719770039',
                     'actionTriggered' => true,
+                    'revision' => '15',
                     'decision' =>  [
                         'experimentId' => '7716830082',
                         'variationId' => '7722370027',
@@ -167,8 +171,9 @@ public function testCreateConversionEventWithAttributesNoValue()
                 'projectId' => '7720880029',
                 'accountId' => '1592310167',
                 'visitorId' => 'testUserId',
+                'revision' => '15',
                 'clientEngine' => 'php-sdk',
-                'clientVersion' => '1.0.1',
+                'clientVersion' => '1.1.0',
                 'isGlobalHoldback' => false,
                 'timestamp' => time() * 1000,
                 'eventFeatures' => [],
@@ -178,6 +183,7 @@ public function testCreateConversionEventWithAttributesNoValue()
                 'layerStates' => [[
                     'layerId' => '7719770039',
                     'actionTriggered' => true,
+                    'revision' => '15',
                     'decision' =>  [
                         'experimentId' => '7716830082',
                         'variationId' => '7722370027',
@@ -220,12 +226,20 @@ public function testCreateConversionEventNoAttributesWithValue()
                 'projectId' => '7720880029',
                 'accountId' => '1592310167',
                 'visitorId' => 'testUserId',
+                'revision' => '15',
                 'clientEngine' => 'php-sdk',
-                'clientVersion' => '1.0.1',
+                'clientVersion' => '1.1.0',
                 'userFeatures' => [],
                 'isGlobalHoldback' => false,
                 'timestamp' => time() * 1000,
-                'eventFeatures' => [],
+                'eventFeatures' => [
+                    [
+                        'name' => 'revenue',
+                        'type' => 'custom',
+                        'value' => 42,
+                        'shouldIndex' => false
+                    ]
+                ],
                 'eventMetrics' => [[
                     'name' => 'revenue',
                     'value' => 42
@@ -235,6 +249,7 @@ public function testCreateConversionEventNoAttributesWithValue()
                 'layerStates' => [[
                     'layerId' => '7719770039',
                     'actionTriggered' => true,
+                    'revision' => '15',
                     'decision' =>  [
                         'experimentId' => '7716830082',
                         'variationId' => '7722370027',
@@ -251,7 +266,7 @@ public function testCreateConversionEventNoAttributesWithValue()
             [$this->config->getExperimentFromKey('test_experiment')],
             $this->testUserId,
             null,
-            42
+            array('revenue' => 42)
         );
 
         $this->assertEquals($expectedLogEvent, $logEvent);
@@ -265,11 +280,25 @@ public function testCreateConversionEventWithAttributesWithValue()
                 'projectId' => '7720880029',
                 'accountId' => '1592310167',
                 'visitorId' => 'testUserId',
+                'revision' => '15',
                 'clientEngine' => 'php-sdk',
-                'clientVersion' => '1.0.1',
+                'clientVersion' => '1.1.0',
                 'isGlobalHoldback' => false,
                 'timestamp' => time() * 1000,
-                'eventFeatures' => [],
+                'eventFeatures' => [
+                    [
+                        'name' => 'revenue',
+                        'type' => 'custom',
+                        'value' => 42,
+                        'shouldIndex' => false
+                    ],
+                    [
+                        'name' => 'non-revenue',
+                        'type' => 'custom',
+                        'value' => 'definitely',
+                        'shouldIndex' => false
+                    ]
+                ],
                 'eventMetrics' => [[
                     'name' => 'revenue',
                     'value' => 42
@@ -279,6 +308,7 @@ public function testCreateConversionEventWithAttributesWithValue()
                 'layerStates' => [[
                     'layerId' => '7719770039',
                     'actionTriggered' => true,
+                    'revision' => '15',
                     'decision' =>  [
                         'experimentId' => '7716830082',
                         'variationId' => '7722370027',
@@ -307,7 +337,70 @@ public function testCreateConversionEventWithAttributesWithValue()
             [$this->config->getExperimentFromKey('test_experiment')],
             $this->testUserId,
             $userAttributes,
-            42
+            array(
+                'revenue' => 42,
+                'non-revenue' => 'definitely'
+            )
+        );
+
+        $this->assertEquals($expectedLogEvent, $logEvent);
+    }
+
+    public function testCreateConversionEventNoAttributesWithInvalidValue()
+    {
+        $expectedLogEvent = new LogEvent(
+            'https://logx.optimizely.com/log/event',
+            [
+                'projectId' => '7720880029',
+                'accountId' => '1592310167',
+                'visitorId' => 'testUserId',
+                'revision' => '15',
+                'clientEngine' => 'php-sdk',
+                'clientVersion' => '1.1.0',
+                'userFeatures' => [],
+                'isGlobalHoldback' => false,
+                'timestamp' => time() * 1000,
+                'eventFeatures' => [
+                    [
+                        'name' => 'revenue',
+                        'type' => 'custom',
+                        'value' => 42,
+                        'shouldIndex' => false
+                    ],
+                    [
+                        'name' => 'non-revenue',
+                        'type' => 'custom',
+                        'value' => 'definitely',
+                        'shouldIndex' => false
+                    ]
+                ],
+                'eventMetrics' => [],
+                'eventEntityId' => '7718020063',
+                'eventName' => 'purchase',
+                'layerStates' => [[
+                    'layerId' => '7719770039',
+                    'actionTriggered' => true,
+                    'revision' => '15',
+                    'decision' =>  [
+                        'experimentId' => '7716830082',
+                        'variationId' => '7722370027',
+                        'isLayerHoldback' => false
+                    ]
+                ]]
+            ],
+            'POST',
+            ['Content-Type' => 'application/json']
+        );
+        $logEvent = $this->eventBuilder->createConversionEvent(
+            $this->config,
+            'purchase',
+            [$this->config->getExperimentFromKey('test_experiment')],
+            $this->testUserId,
+            null,
+            array(
+                'revenue' => '42',
+                'non-revenue' => 'definitely'
+            )
         );
 
         $this->assertEquals($expectedLogEvent, $logEvent);
diff --git a/tests/OptimizelyTest.php b/tests/OptimizelyTest.php
index fef5622f..d23dae19 100644
--- a/tests/OptimizelyTest.php
+++ b/tests/OptimizelyTest.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Copyright 2016, Optimizely
+ * Copyright 2016-2017, Optimizely
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -649,6 +649,61 @@ public function testTrackWithAttributesNoEventValue()
         $optlyObject->track('purchase', 'test_user', $userAttributes);
     }
 
+    public function testTrackNoAttributesWithDeprecatedEventValue()
+    {
+        $this->eventBuilderMock->expects($this->once())
+            ->method('createConversionEvent')
+            ->with(
+                $this->projectConfig,
+                'purchase',
+                [$this->projectConfig->getExperimentFromKey('group_experiment_1'),
+                    $this->projectConfig->getExperimentFromKey('group_experiment_2')],
+                'test_user',
+                null,
+                array('revenue' => 42)
+            )
+            ->willReturn(new LogEvent('logx.optimizely.com/track', ['param1' => 'val1'], 'POST', []));
+
+        $this->loggerMock->expects($this->exactly(7))
+            ->method('log');
+        $this->loggerMock->expects($this->at(0))
+            ->method('log')
+            ->with(Logger::WARNING,
+                'Event value is deprecated in track call. Use event tags to pass in revenue value instead.');
+        $this->loggerMock->expects($this->at(1))
+            ->method('log')
+            ->with(Logger::INFO, 'User "test_user" does not meet conditions to be in experiment "test_experiment".');
+        $this->loggerMock->expects($this->at(2))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Not tracking user "test_user" for experiment "test_experiment".');
+        $this->loggerMock->expects($this->at(3))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Experiment "paused_experiment" is not running.');
+        $this->loggerMock->expects($this->at(4))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Not tracking user "test_user" for experiment "paused_experiment".');
+        $this->loggerMock->expects($this->at(5))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Tracking event "purchase" for user "test_user".');
+        $this->loggerMock->expects($this->at(6))
+            ->method('log')
+            ->with(Logger::DEBUG,
+                'Dispatching conversion event to URL logx.optimizely.com/track with params param1=val1.');
+
+        $optlyObject = new Optimizely($this->datafile, new ValidEventDispatcher(), $this->loggerMock);
+
+        $eventBuilder = new \ReflectionProperty(Optimizely::class, '_eventBuilder');
+        $eventBuilder->setAccessible(true);
+        $eventBuilder->setValue($optlyObject, $this->eventBuilderMock);
+
+        // Call track
+        $optlyObject->track('purchase', 'test_user', null, 42);
+    }
+
     public function testTrackNoAttributesWithEventValue()
     {
         $this->eventBuilderMock->expects($this->once())
@@ -660,7 +715,7 @@ public function testTrackNoAttributesWithEventValue()
                     $this->projectConfig->getExperimentFromKey('group_experiment_2')],
                 'test_user',
                 null,
-                42
+                array('revenue' => 42)
             )
             ->willReturn(new LogEvent('logx.optimizely.com/track', ['param1' => 'val1'], 'POST', []));
 
@@ -697,10 +752,62 @@ public function testTrackNoAttributesWithEventValue()
         $eventBuilder->setValue($optlyObject, $this->eventBuilderMock);
 
         // Call track
-        $optlyObject->track('purchase', 'test_user', null, 42);
+        $optlyObject->track('purchase', 'test_user', null, array('revenue' => 42));
     }
 
-    public function testTrackWithAttributesWithEventValue()
+    public function testTrackNoAttributesWithInvalidEventValue()
+    {
+        $this->eventBuilderMock->expects($this->once())
+            ->method('createConversionEvent')
+            ->with(
+                $this->projectConfig,
+                'purchase',
+                [$this->projectConfig->getExperimentFromKey('group_experiment_1'),
+                    $this->projectConfig->getExperimentFromKey('group_experiment_2')],
+                'test_user',
+                null,
+                array('revenue' => '4200')
+            )
+            ->willReturn(new LogEvent('logx.optimizely.com/track', ['param1' => 'val1'], 'POST', []));
+
+        $callIndex = 0;
+        $this->loggerMock->expects($this->exactly(6))
+            ->method('log');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::INFO, 'User "test_user" does not meet conditions to be in experiment "test_experiment".');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Not tracking user "test_user" for experiment "test_experiment".');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Experiment "paused_experiment" is not running.');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Not tracking user "test_user" for experiment "paused_experiment".');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Tracking event "purchase" for user "test_user".');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::DEBUG,
+                'Dispatching conversion event to URL logx.optimizely.com/track with params param1=val1.');
+
+        $optlyObject = new Optimizely($this->datafile, new ValidEventDispatcher(), $this->loggerMock);
+
+        $eventBuilder = new \ReflectionProperty(Optimizely::class, '_eventBuilder');
+        $eventBuilder->setAccessible(true);
+        $eventBuilder->setValue($optlyObject, $this->eventBuilderMock);
+
+        // Call track
+        $optlyObject->track('purchase', 'test_user', null, array('revenue' => '4200'));
+    }
+
+    public function testTrackWithAttributesWithDeprecatedEventValue()
     {
         $userAttributes = [
             'device_type' => 'iPhone',
@@ -716,32 +823,36 @@ public function testTrackWithAttributesWithEventValue()
                     $this->projectConfig->getExperimentFromKey('group_experiment_2')],
                 'test_user',
                 $userAttributes,
-                42
+                array('revenue' => 42)
             )
             ->willReturn(new LogEvent('logx.optimizely.com/track', ['param1' => 'val1'], 'POST', []));
 
-        $this->loggerMock->expects($this->exactly(6))
+        $this->loggerMock->expects($this->exactly(7))
             ->method('log');
         $this->loggerMock->expects($this->at(0))
             ->method('log')
-            ->with(Logger::INFO, 'User "test_user" does not meet conditions to be in experiment "test_experiment".');
+            ->with(Logger::WARNING,
+                'Event value is deprecated in track call. Use event tags to pass in revenue value instead.');
         $this->loggerMock->expects($this->at(1))
+            ->method('log')
+            ->with(Logger::INFO, 'User "test_user" does not meet conditions to be in experiment "test_experiment".');
+        $this->loggerMock->expects($this->at(2))
             ->method('log')
             ->with(Logger::INFO,
                 'Not tracking user "test_user" for experiment "test_experiment".');
-        $this->loggerMock->expects($this->at(2))
+        $this->loggerMock->expects($this->at(3))
             ->method('log')
             ->with(Logger::INFO,
                 'Experiment "paused_experiment" is not running.');
-        $this->loggerMock->expects($this->at(3))
+        $this->loggerMock->expects($this->at(4))
             ->method('log')
             ->with(Logger::INFO,
                 'Not tracking user "test_user" for experiment "paused_experiment".');
-        $this->loggerMock->expects($this->at(4))
+        $this->loggerMock->expects($this->at(5))
             ->method('log')
             ->with(Logger::INFO,
                 'Tracking event "purchase" for user "test_user".');
-        $this->loggerMock->expects($this->at(5))
+        $this->loggerMock->expects($this->at(6))
             ->method('log')
             ->with(Logger::DEBUG,
                 'Dispatching conversion event to URL logx.optimizely.com/track with params param1=val1.');
@@ -755,4 +866,61 @@ public function testTrackWithAttributesWithEventValue()
         // Call track
         $optlyObject->track('purchase', 'test_user', $userAttributes, 42);
     }
+
+    public function testTrackWithAttributesWithEventValue()
+    {
+        $userAttributes = [
+            'device_type' => 'iPhone',
+            'company' => 'Optimizely'
+        ];
+
+        $this->eventBuilderMock->expects($this->once())
+            ->method('createConversionEvent')
+            ->with(
+                $this->projectConfig,
+                'purchase',
+                [$this->projectConfig->getExperimentFromKey('group_experiment_1'),
+                    $this->projectConfig->getExperimentFromKey('group_experiment_2')],
+                'test_user',
+                $userAttributes,
+                array('revenue' => 42)
+            )
+            ->willReturn(new LogEvent('logx.optimizely.com/track', ['param1' => 'val1'], 'POST', []));
+
+        $callIndex = 0;
+        $this->loggerMock->expects($this->exactly(6))
+            ->method('log');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::INFO, 'User "test_user" does not meet conditions to be in experiment "test_experiment".');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Not tracking user "test_user" for experiment "test_experiment".');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Experiment "paused_experiment" is not running.');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Not tracking user "test_user" for experiment "paused_experiment".');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::INFO,
+                'Tracking event "purchase" for user "test_user".');
+        $this->loggerMock->expects($this->at($callIndex++))
+            ->method('log')
+            ->with(Logger::DEBUG,
+                'Dispatching conversion event to URL logx.optimizely.com/track with params param1=val1.');
+
+        $optlyObject = new Optimizely($this->datafile, new ValidEventDispatcher(), $this->loggerMock);
+
+        $eventBuilder = new \ReflectionProperty(Optimizely::class, '_eventBuilder');
+        $eventBuilder->setAccessible(true);
+        $eventBuilder->setValue($optlyObject, $this->eventBuilderMock);
+
+        // Call track
+        $optlyObject->track('purchase', 'test_user', $userAttributes, array('revenue' => 42));
+    }
 }
diff --git a/tests/ProjectConfigTest.php b/tests/ProjectConfigTest.php
index 18c6f20a..c378c978 100644
--- a/tests/ProjectConfigTest.php
+++ b/tests/ProjectConfigTest.php
@@ -181,6 +181,11 @@ public function testGetProjectId()
         $this->assertEquals('7720880029', $this->config->getProjectId());
     }
 
+    public function testGetRevision()
+    {
+        $this->assertEquals('15', $this->config->getRevision());
+    }
+
     public function testGetGroupValidId()
     {
         $group = $this->config->getGroup('7722400015');
diff --git a/tests/TestData.php b/tests/TestData.php
index d5f62a4c..ee3f5df7 100644
--- a/tests/TestData.php
+++ b/tests/TestData.php
@@ -23,7 +23,7 @@
 
 define('DATAFILE',
     '{"experiments": [{"status": "Running", "key": "test_experiment", "layerId": "7719770039", 
-    "trafficAllocation": [{"entityId": "7722370027", "endOfRange": 4000}, 
+    "trafficAllocation": [{"entityId": "", "endOfRange": 1500}, {"entityId": "7722370027", "endOfRange": 4000}, 
     {"entityId": "7721010009", "endOfRange": 8000}], "audienceIds": ["7718080042"], 
     "variations": [{"id": "7722370027", "key": "control"}, {"id": "7721010009", "key": "variation"}], 
     "forcedVariations": {"user1": "control"}, "id": "7716830082"}, {"status": "Paused", "key": "paused_experiment", "layerId": "7719779139", 
@@ -32,7 +32,7 @@
     "variations": [{"id": "7722370427", "key": "control"}, {"id": "7721010509", "key": "variation"}], 
     "forcedVariations": {}, "id": "7716830585"}], "version": "2", 
     "audiences": [{"conditions": "[\"and\", [\"or\", [\"or\", {\"name\": \"device_type\", \"type\": \"custom_attribute\", \"value\": \"iPhone\"}]], [\"or\", [\"or\", {\"name\": \"location\", \"type\": \"custom_attribute\", \"value\": \"San Francisco\"}]]]", "id": "7718080042", "name": "iPhone users in San Francisco"}], 
-    "groups": [{"policy": "random", "trafficAllocation": [{"entityId": "7723330021", "endOfRange": 2000}, {"entityId": "7718750065", "endOfRange": 6000}], "experiments": [{"status": "Running", "key": "group_experiment_1", "layerId": "7721010011", "trafficAllocation": [{"entityId": "7722260071", "endOfRange": 5000}, {"entityId": "7722360022", "endOfRange": 10000}], "audienceIds": [], "variations": [{"id": "7722260071", "key": "group_exp_1_var_1"}, {"id": "7722360022", "key": "group_exp_1_var_2"}], "forcedVariations": {"user1": "group_exp_1_var_1"}, "id": "7723330021"}, {"status": "Running", "key": "group_experiment_2", "layerId": "7721020020", "trafficAllocation": [{"entityId": "7713030086", "endOfRange": 5000}, {"entityId": "7725250007", "endOfRange": 10000}], "audienceIds": [], 
+    "groups": [{"policy": "random", "trafficAllocation": [{"entityId": "", "endOfRange": 500}, {"entityId": "7723330021", "endOfRange": 2000}, {"entityId": "7718750065", "endOfRange": 6000}], "experiments": [{"status": "Running", "key": "group_experiment_1", "layerId": "7721010011", "trafficAllocation": [{"entityId": "7722260071", "endOfRange": 5000}, {"entityId": "7722360022", "endOfRange": 10000}], "audienceIds": [], "variations": [{"id": "7722260071", "key": "group_exp_1_var_1"}, {"id": "7722360022", "key": "group_exp_1_var_2"}], "forcedVariations": {"user1": "group_exp_1_var_1"}, "id": "7723330021"}, {"status": "Running", "key": "group_experiment_2", "layerId": "7721020020", "trafficAllocation": [{"entityId": "7713030086", "endOfRange": 5000}, {"entityId": "7725250007", "endOfRange": 10000}], "audienceIds": [], 
     "variations": [{"id": "7713030086", "key": "group_exp_2_var_1"}, {"id": "7725250007", "key": "group_exp_2_var_2"}], "forcedVariations": {}, "id": "7718750065"}], "id": "7722400015"}], 
     "attributes": [{"id": "7723280020", "key": "device_type"}, {"id": "7723340004", "key": "location"}], 
     "projectId": "7720880029", "accountId": "1592310167", 
diff --git a/tests/UtilsTests/EventTagUtilsTest.php b/tests/UtilsTests/EventTagUtilsTest.php
new file mode 100644
index 00000000..1e44b6b9
--- /dev/null
+++ b/tests/UtilsTests/EventTagUtilsTest.php
@@ -0,0 +1,50 @@
+<?php
+/**
+ * Copyright 2017, Optimizely
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Optimizely\Tests;
+
+use Optimizely\Utils\EventTagUtils;
+
+class EventTagUtilsTest extends \PHPUnit_Framework_TestCase
+{
+    public function testGetRevenueValueInvalidArgs() {
+        $this->assertNull(EventTagUtils::getRevenueValue(null));
+        $this->assertNull(EventTagUtils::getRevenueValue(0.5));
+        $this->assertNull(EventTagUtils::getRevenueValue(65536));
+        $this->assertNull(EventTagUtils::getRevenueValue(9223372036854775807));
+        $this->assertNull(EventTagUtils::getRevenueValue('65536'));
+        $this->assertNull(EventTagUtils::getRevenueValue(true));
+    }
+    public function testGetRevenueValueNoRevenueTag() {
+        $this->assertNull(EventTagUtils::getRevenueValue(array()));
+        $this->assertNull(EventTagUtils::getRevenueValue(array('non-revenue' => 42)));
+    }
+
+    public function testGetRevenueValueWithInvalidRevenueTag() {
+        $this->assertNull(EventTagUtils::getRevenueValue(array('revenue' => null)));
+        $this->assertNull(EventTagUtils::getRevenueValue(array('revenue' => 0.5)));
+        $this->assertNull(EventTagUtils::getRevenueValue(array('revenue' => '65536')));
+        $this->assertNull(EventTagUtils::getRevenueValue(array('revenue' => true)));
+        $this->assertNull(EventTagUtils::getRevenueValue(array('revenue' => array(1, 2, 3))));
+    }
+
+    public function testGetRevenueValueWithRevenueTag() {
+        $this->assertEquals(65536, EventTagUtils::getRevenueValue(array('revenue' => 65536)));
+        $this->assertEquals(9223372036854775807, EventTagUtils::getRevenueValue(array('revenue' => 9223372036854775807)));
+        $this->assertEquals(0, EventTagUtils::getRevenueValue(array('revenue' => 0)));
+    }
+}
diff --git a/tests/UtilsTests/ValidatorTest.php b/tests/UtilsTests/ValidatorTest.php
index bfdd156f..175f2bcd 100644
--- a/tests/UtilsTests/ValidatorTest.php
+++ b/tests/UtilsTests/ValidatorTest.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Copyright 2016, Optimizely
+ * Copyright 2016-2017, Optimizely
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -72,6 +72,37 @@ public function testAreAttributesValidInvalidAttributes()
         $this->assertFalse(Validator::areAttributesValid([0, 1, 2, 42, 'abc' => 'def']));
     }
 
+    public function testAreEventTagsValidValidEventTags()
+    {
+        // Empty attributes
+        $this->assertTrue(Validator::areEventTagsValid([]));
+
+        // Valid attributes
+        $this->assertTrue(Validator::areEventTagsValid([
+            'revenue' => 0,
+            'location' => 'San Francisco',
+            'browser' => 'Firefox'
+        ]));
+    }
+
+    public function testAreEventTagsValidInvalidEventTags()
+    {
+        // String as attributes
+        $this->assertFalse(Validator::areEventTagsValid('Invalid string attributes.'));
+
+        // Integer as attributes
+        $this->assertFalse(Validator::areEventTagsValid(42));
+
+        // Boolean as attributes
+        $this->assertFalse(Validator::areEventTagsValid(true));
+
+        // Sequential array as attributes
+        $this->assertFalse(Validator::areEventTagsValid([0, 1, 2, 42]));
+
+        // Mixed array as attributes
+        $this->assertFalse(Validator::areEventTagsValid([0, 1, 2, 42, 'abc' => 'def']));
+    }
+
     public function testIsUserInExperimentNoAudienceUsedInExperiment()
     {
         $config = new ProjectConfig(DATAFILE, new NoOpLogger(), new NoOpErrorHandler());