Google To "Out Open" Facebook On November 5
techcrunch.com
techcrunch.com
http://mindrosity.blogspot.com/2007/09/how-google-could-beat...
Google on the other hand is about finding stuff, which can sometimes be achieved by clicking on an ad.
facebook definitely has a potential X that could be as profitable (or moreso) than adsense. but what that is i don't know. i'm sure they do though.