I'm pretty sure they're not using much metadata, but instead using collaborative filtering based on the libraries other iTunes users. "Apple's proprietary reco

I'm pretty sure they're not using much metadata, but instead using collaborative filtering based on the libraries other iTunes users. "Apple's proprietary recommendation engine that uses collaborative filtering and iTunes' built-in rating system to generate music recommendations" from http://www.appleinsider.com/articles/09/03/24/apple_switches_on_itunes_genius_for_videos.html http://www.appleinsider.com/articles/09/03/24/apple_switches...