I remember someone telling me a story about the delivery of the first copy of MS DOS to Japan. (I don't know if this story is true, but it's a good story.) The shipment contained a copy of DOS on paper tape and a blank roll of tape. They taxed just the blank one because the one with DOS on it was "used".
So... Does this make Amazon.com a "used comment salesman" and Six Apart a seller of "new comment space"?
I'm of course mostly joking, but I think this represents two completely different views on the "media" business. You can sell the blank media or "used media". Either the comments are the product or the ability to create comments is the product. This is what separates the professional world from the amateur world... But good amateur can exceed crappy professional in quality. Production and distribution are becoming lower cost, and two opposed views of the world are colliding harder. Clearly, clever people have managed to arbitrage/manage both of these models, but they surely produce very different types of laws, processes and world-views.