They give links to buy the music from amazon, and take commission. Its only a matter of time before they go broke and we can use the service add free
oh yeah, that reminds me of a site im going to create when i finish my gcse's.
Its wil be called whatmusic or something, it will work by uploading your playlists automatically (using the same software those signiture scripts use), then it compares your playlists with other people's playlists, and give recoomendations about what songs it thinks you will like.