Complex systems, writes Clay Shirky, have a habit of collapsing catastrophically, and that, he says, is the best way to understand what's happened to big media since the arrival of the Internet. About 15 years ago, the supply part of media’s supply-and-demand curve went parabolic, with a predictably inverse effect on price. Since then, a battalion of media elites have lined up to declare that exactly the opposite thing will start happening any day now. To pick a couple of examples more or less at random, last year Barry Diller of IAC said, of content available on the...