A note from the publisher says Jeremy Rifkin himself asked them to ship me a copy of his latest book, The Zero Marginal Cost Society. It’s obvious why: in writing about the economics of open-source software, he thinks I provided one of the paradigmatic cases of what he wants to write about – the displacement of markets in scarce goods by zero-marginal-cost production. Rifkin’s book is an extended argument that this is is a rising trend which will soon obsolesce not just capitalism as we have known it, but many forms of private property as well.