Facebook Ramps Up Revenue Push - WSJ.com
Eric Barker stashed this in Facebook!
I can't read this article thanks to WSJ's pay wall.
But we can assume the big money is either a variation on Google AdSense, Apple iAds, Skype, or Paypal: http://techcrunch.com/2012/05/17/how-facebook-could-make-more-money/
By the way, guess who called this two years ago: http://techcrunch.com/2010/10/02/facebook-bigger-google/
Fun trick: take the title of any paywalled WSJ article and pump it into Google. First result will be the article. Click on it. Non-paywall version.
Brilliant. Why do they insist on paywalls?