To me, the most fascinating thing about this chart of media concentration (link via Larry Lessig) is that I find myself constantly surprised at the staggering diversity of media venues that are owned by a single corporation. I would probably not have guessed that CNN, WB, and HBO are all owned by the same company (AOL/Time Warner), much less that the same company also owned Warner Brothers studios, Time magazine, Entertainment Weekly, Columbia House music, and Back Bay books, among many others.

So while some might view this chart and be alarmed by the supposed lack of diversity, I (playing devil's advocate) would argue that the chart implies the opposite. I.e., I think the chart implies that oligopolistic ownership may still produce incredible diversity of content. Indeed, that's precisely why I was surprised -- the diversity of content would have led me to expect diversity of ownership. This chart handily demonstrates that the two types of diversity aren't necessarily correlated.