Who says you can't "compete with free"?

Mike at Techdirt has a brilliant explanation of the economics behind "free". 

"Getting back to my series of posts on understanding economics when scarcity is removed from some goods, I wanted to address the ridiculousness of the "can't compete with free" statements that people love to throw out. If we break down the statement carefully, anyone who says that is really saying that they can't compete at all. The free part is actually meaningless -- but the zero is blinding everyone.

To explain this, it helps to go back to your basic economics class and recognize that, in a competitive market, the price of a good is always going to get pushed towards its marginal cost. That actually makes a lot of sense. As competition continues, it puts pressure on profits, but producers aren't willing (or can't for very long) keep selling goods at a direct loss. Sunk (or fixed) costs don't matter, because they've already been paid -- so everything gets pushed to marginal cost. That's pretty well accepted by most folks -- but it's still misinterpreted by many. They tend to look at it and say that if price equals marginal cost, then no one would ever produce anything. That's a misconception that is at the heart of this whole debate."