That the marginal cost of copying media is zero is a pretty mundane observation. The author goes beyond this to hypothesize that demand moves according to some

That the marginal cost of copying media is zero is a pretty mundane observation. The author goes beyond this to hypothesize that demand moves according to some abstract "fair price" (that happens to suit the author's semi-Marxist definition of fairness), and that piracy only occurs when the market price is set above this value. This second point is the only novel bit of the author's post, and it's just not very good.