The guessing games over Facebook's worth are back on again. They were reignited by the news on May 26 that Facebook has accepted a $200 million investment that values the company at $10 billion.

Much of the discussion centers on the ability, or lack thereof, of Facebook and other social networks to sell advertising and deliver advertising results. People get on Facebook to socialize, not hunt for products—or so the argument runs.

But that argument misses the point. The question isn't how advertising will work on Facebook but rather how Facebook and social networks like News Corp.'s (NWS) MySpace are changing advertising. I'm loath to affix the 2.0 moniker to yet another phrase, but if ever an industry needed to be 2.0-ized, it's advertising.