While Google had been making money in the mobile space from their typical search ads when users Googled something, AdMob brought them a platform to make money from web display ads and app display ads.

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In hearings before the Federal Trade Commission, Google successfully argued that it should be allowed to acquire DoubleClick, the world's largest display-advertising firm, because search ads and display ads are separate markets with no related competitive forces.

FORBES: Magazine Article

The online ad management firm, known until recently as SearchIgnite, said spending rose across the three channels it tracks: search ads, display ads, and Facebook.

FORBES: Google and Facebook Lead Strong Q2 Online Ad Spending