(besides a name that doesn't sound like they only sell music...) If you don't know what the iTunes Music Store is, then read no further.
They already have unique usernames (accounts) for everyone. They already have a linking system where I can send you a clickable link to go look at an album. In iChat, for Mac users, you can show the current song you are listening to as your status message, so I can see what all my friends are listening to at the moment. You can click the link and listen to a preview of the song on iTMS. That feature is a year or two old, and I have had many conversations that start by a comment on the current song.
So imagine this! Instead of me sending you an iTMS link that looks like
http://phobos.apple.com/WebObjects/MZStore.woa/wa/viewAlbum?id=135988273&s=143441
Why not have a an additional affiliate parameter that was unique to my account, like:
http://phobos.apple.com/WebObjects/MZStore.woa/wa/viewAlbum?id=135988273&s=143441&aff=1234567
This is like what Revver does. If I send you to an album and you buy that entire album, I should get a small credit added to my account. $0.99 (one song) seems like a reasonable amount. If you only buy less than the full album, I could get a smaller amount like $0.09 or $0.05 per song. Peer tastes and word-of-mouth already have a huge impact on sales in the music industry.
And the artists themselves can get involved. They already have the clever idea of celebrity playlists, but why not pay the celebrity by how much revenue their playlist generates? The same goes for their "non-celebrity" playlists that they call iMixes.
As usual, the e-commerce pioneer Amazon.com has had an affiliate program for years now. Just imagine how many more sales iTMS could have if all of us bloggers were putting links to the iTunes Music Store in our blog entries or sidebars in the hopes of getting a few songs worth of credit out of our readers' clicks! Can't you just see all the little myspace kiddies exchanging iTunes links like mad?
They should shorten the urls, though. The Revver urls are beautiful in their simplicity (e.g. http://revver.com/video/50455/20700).
Just and idea...and Apple is probably developing this already....
I reserve the right to point you back to this prophecy when it becomes true in the future.