GOOGLE deal Finalized
MOUNTAIN VIEW, Calif., (March 11, 2008) – Google Inc. (NASDAQ: GOOG) announced today that it has completed its acquisition of DoubleClick, a company that offers online ad serving and management technology to advertisers, web publishers and ad agencies.
source: google press center
There is a reason to do this bcoz of the heavy manipulation in Search Engines by many SEO's which is causing the headache and i think this might be the reason for Google to act upon.
Conclusion: Ranking would be much tougher than ever before so SEO guys need to watch out