Maybe I am on to something here...
Publicis acquires Digitas for $1.3 billion
Yahoo! acquires Right Media for $680 million
Google acquires DoubleClick for $3.1 billion
WPP acquires 24/7 Real Media for $649 million
Microsoft acquires aQuantive for $6 billion
And (on the smaller side), AOL acquires Adtech and ThirdScreenMedia
Microsoft acquires ScreenTonic
Seems the connections are getting thicker...