While this idea seems similar to Ping for iTunes, I think it has merit as another channel for music discovery. From what is described in the post, however, it seems like it would be more difficult to build and manage than it needs to be. Why resell from the site and go through headaches of profit splitting, when you can just redirect to iTunes, Amazon, etc?
I hear that artists only receive like 15-20% of the itunes price. That a market inefficiency that I want to fix.