Good thought experiment by Derek Powazek: “What if Social Networks Just Aren’t Profitable?”
Here’s the short version: Every community-based site in the history of the web has essentially been a stab at creating a social network. Most of them fail as businesses, with the rare exception of small, lucky communities that become self-sufficient but not exactly prosperous. What if that’s just the way it is?
I’d say there’s a lot of evidence for the thesis and not much agin’ it. There’s also “profitable” and “PROFITABLE”. Maybe the profits in social networks just don’t scale to the level of publicly traded corporations. Doesn’t mean a nice living can’t be made at the Main Street or regional level.