This article does a good job reminding us how the world of media has changed in the past few decades.

The metaphors we use to think about changes in media have a lot to tell us about the particular moment we’re in. McLuhan talked about media as an extension of our central nervous system, and we spent forty years trying to figure out how media was re-wiring our brains. The metaphor you hear now is different, more E.O. Wilson than McLuhan: the ecosystem. I happen to think that this is a useful way of thinking about what’s happening to us now: today’s media is in fact much closer to a real-world ecosystem in the way it circulates information than it is like the old industrial, top-down models of mass media. It’s a much more diverse and interconnected world, a system of flows and feeds – completely different from an assembly line. That complexity is what makes it so interesting, of course, but also what makes it so hard to predict what it’s going to look like in five or ten years. So instead of starting with the future, I propose that we look to the past. — Steven Berlin Johnson