README.md

Ad Prices Extension

This directory contains the code for the data collection extension, which collects ads, metadata, and bidding information for each ad.

First Time Setup

Install dependencies from npm

npm install

Building and running the extension

This extension is a Typescript + React project, we use a webpack-based toolchain to compile into JavaScript.

Compile the extension:

npm run build

Alternatively, to compile the extension automatically when you save a file, you can run:

webpack --watch

Load the extension in the browser

• Go to chrome://extensions
• At the top right of the top bar, turn on Developer mode if it is not on already
• Click "Load Unpacked"
• Select the dist/ folder in this repository

How do we find the amount bid to run an ad?

The amount advertisers bid to run the ad is sometimes leaked by prebid.js, an open source header bidding library that is popular on many websites.

You can tell if a site leaks this information by going to the Developer Tools, opening the JavaScript console, and typing "pbjs". If it returns an object, then the site is using a vulnerable version of prebid.

Some sites that use pbjs:

• vox.com
• espn.com
• militarytimes.com
• dailyherald.com
• zdnet.com
• androidauthority.com
• askmen.com
• startribune.com
• katu.com
• billboard.com
• bostonglobe.com
• wpxi.com
• avclub.com

What functions will give us the bids?

Based on the prebid.js documentation, it looks like calling the following functions will give us relevant info:

• pbjs.getBidResponses() will show all of the bids for each ad slot (see the cpm field for the value), though not necessarily the winner
• pbjs.getAllWinningBids() will show bids that have won and are on the page
• pbjs.getAllPrebidWinningBids() will show bids that have won but haven't yet rendered on the page.