My thought is that iTunes provides opportunities for authors/publishers to distribute their works electronically, much like those media available from eBay. I wonder which is a better deal as a buyer, versus as a seller?
There was an analysis similar to this, but comparing eBay to Yahoo Auctions to uBid. I think it indicated that uBid was better for sellers in certain categories, and eBay was better for buyers in those same categories. I can't recall which, though.
Regardless, I'm interested to see where Apple takes its iTunes business model, and if Google or Microsoft try to copy it.