It could have been amusing if the winning song was something obscure, like a no-name musician's cover of a TV theme song or some 10-minute electronic piece. I wonder if they secretly reject the winner in favor of the first runner-up who bought something cool.
I think every one of these contests has ended up being a big name artist. It does seem odd. What if the actual 10 billionth song was "I F***** Your Wife" by Anal C**t (yes, it's a real song and band, go look it up)? I don't think Apple would be choosing that as the winner.