Google acquired DoubleClick in 2007 for $3.1 billion, strengthening its online advertising business.
Google announced the agreement in April 2007 and completed the acquisition in March 2008 after regulatory review. DoubleClick supplied ad-serving technology used by publishers and advertisers to manage digital advertising.
The purchase complemented Google’s existing search-advertising business. It gave Google a stronger position in display advertising, where ads appear on websites rather than only beside search results.
The acquisition attracted scrutiny because Google and DoubleClick held extensive data and advertising capabilities. A common mix-up is with Google’s 2009 purchase of AdMob, a mobile-advertising company; DoubleClick was the earlier and substantially larger desktop-web advertising deal.