Let’s say you’re a huge Neil Diamond freak (hypothetically), go to pandora.com, type Neil into the prompt and what happens next is just too perfect. You get you’re own streaming “station” on which you can listen to artists that are similar to Neil using an analysis that compares up to 400 musical characteristics. From that station you can buy tracks from iTunes, buy albums from Amazon, add it to your favorites page, rate the song, or make a new station from that song. If you’ve got a station you can’t keep to yourself, you can email it to a friend.
Pandora is awesome
Take a listen to some DJ Shadow Radio: http://www.pandora.com/?sc=sh2827087