- a Last.fm account
- Mozilla Firefox with the GreaseMonkey extension
(Sorry, Google Chrome supports GreaseMonkey but doesn't support GM_get, GM_set and GM_xmlhttpRequest.)
- install this script
- visit Deezer and follow the instructions to allow the application to access your Last.fm account.
It will then scrobble all the time, as long as GreaseMonkey is active.
It should be pretty trivial to adapt to any other website with the artist and track in the title of the page. As a bonus this works on accuradio.com's player.