P2P's effect on music sales

Does file-sharing affect music sales? I guess the answer depends on who you're asking. This article on The Long Tail looks at a fascinating paper that has been released on the economics of P2P file-sharing.

...it does indeed depress music sales overall. But the effect is not felt evenly. The hits at the top of the charts lose sales, but the niche artists further down the popularity curve actually benefit from file-trading.

Well, it seems that if you're a listener of mainstream, label-driven and marketed music, then file-sharing hurts. But then, who needs to support these manufactured musicians anyway? I say, support the niche, indie musicians.

There's another interesting summary of this research here.