Google's Past Ad Acquisitions

The Teracent acquisition comes just two weeks after Google announced it was -- a deal worth a whopping $750 million in stock. AdMob focuses primarily on display ads and mobile application ads. Translation: Get ready to see a whole lot of Google-powered advertising on your mobile phone.

Prior to AdMob, Google's ad-related acquisitions had revolved around the Web and even the airwaves. (Some say the G-gang is also , though I'm pretty sure those rumors are unfounded.) So what are some of the other noteworthy purchases, and how have they affected you? Time for the quick tour:

• DoubleClick: Bought , DoubleClick delivered a massive network of advertisers into Google's already-strong advertising system. You can thank DoubleClick for all the Google-run display and rich-media ads around the Net -- prior to DC's entry, those had been a relatively small part of Google's advertising empire.

• AdScape: In-game advertising firm AdScape in March of 2007, of massive Google-led virtual worlds on the way. To its credit, Google did launch last summer. It took only a matter of months, however, for the service -- which, by some accounts, had turned largely into a -- to .