A long time ago, when Last.fm started, it had the option to play music similar to two or more artists. You would write the artists separated by a comma and you would get a playlist of artists which were similar. That was really good.
A very VERY long time ago was echo.com. It's hard to find any information about it now. But it was a streaming music site that let you rate the artist, album, and song individually with stars, and it would use those ratings to make recommendations to you. Also as you accumulated listening hours you earned Amazon gift certificates. I wish someone out there remembered them besides me.
