[EvilTerran]

"The popular content is downloaded more"? What does that even mean? How are you measuring popularity?

... by units sold, say? Maybe the best-selling content is so because it's downloaded more, not vice-versa as you asserted. Or maybe there's a third factor that causes both. Correlation does not imply causation.

What of those who, as the GP said s/he does, download for free, then buy a copy if they actually like it?

If a product is of unknown quality, but known to be free to copy, it's sound economics to value it at zero. Supply is infinite and demand is indeterminate. Once you know more about it, and know how much you want it, you may want to pay for it. Or you may not, if you don't like it or are a cheapskate. C'est la vie.

It's more likely than you'd think: http://www.guardian.co.uk/music/2009/apr/21/study-finds-pira...