So AOL buys HuffPo for $315m, valuing (as Chris Tolles points out) their 26m ComScore users at $12 each. We're not (yet) in the Broadcast.com league but it's still an excitingly bubbly valuation at ten times 2010 revenues, five times even management's own 2011 revenue forecast and god knows what multiple of the presumably nominal profitability they claim the site achieved in the fifth year since it launched.
AOL is betting the farm on monetising professionally-created content via display advertising. That's a big bet, but of course for AOL it's not a new one - acquiring HuffPo is simply a continuation of the strategy that AOL has been pursuing since it parted company with Time Warner. Engadget, Politics Daily, Techcrunch and especially Patch are all long bets on paying writers and then serving display ads over the results, and if that's the strategy this is a smart push for more of the same.