Future - 7:37 pm on Nov 25, 2009 (gmt 0) Unsure why they never get banned though..
Maybe, Adsense for Search work wells for MFA sites ?
You can easily find many examples online for sites only having search enabled.
(those get traffic from other sources for sure, cause we were able to track 100s of such sites advertising on adbrite or other similar networks, publisheres where #*$! sites).
Unsure why they never get banned though..