"Google Network Revenues - Google's partner sites generated revenues, through AdSense programs, of $2.50 billion, or 30% of total revenues, in the fourth quarter of 2010. This represents a 22% increase from fourth quarter 2009 network revenues of $2.04 billion."
If publishers are paid 68%, this means Google's share is roughly $650mill for that quarter.
You can see their Q4 2010 earnings statement at http://investor.google.com/earnings/2010/Q4_google_earnings.... . Here is the relevant portion for AdSense:
"Google Network Revenues - Google's partner sites generated revenues, through AdSense programs, of $2.50 billion, or 30% of total revenues, in the fourth quarter of 2010. This represents a 22% increase from fourth quarter 2009 network revenues of $2.04 billion."
If publishers are paid 68%, this means Google's share is roughly $650mill for that quarter.