Last week's flurry of corporate buyouts was apparently only a dinner bell.

Google (NASDAQ:GOOG) is coming to the table, announcing a $750 million deal for mobile ad network AdMob.

Cynics will scoff at Google's history of veering into sponsored spaces outside of its dot-com stronghold. Forays into print, radio, and television advertising have been mostly fruitless. Mobile advertising, on the other hand, is a clearer fit for Google's Web-served ads.

Google is already there, to some extent, with DoubleClick Mobile. However, just as it acquired YouTube despite having its own video-sharing offering a couple of years ago, Google wants to make sure that it owns this category.

Mobile advertising is blowing up right now. Google continues to butt heads with Microsoft (NASDAQ:MSFT) and Apple (NASDAQ:AAPL), and the latest battlefield is on the smartphone grid. Did you think the Google Android initiative was only a drill? There will be some serious advertising dollars spent to reach folks buried in their wireless browsers, and if Google didn't snap up AdMob, a competitor would have.

This deal is also noteworthy because it's an all-stock deal. Big G was brokering mostly small deals this year until AdMob, and it decides to pay in stock certificates?

Google has $22 billion in cash and short-term investments on its balance sheet. The consensus is that cash-rich tech monsters Google, Microsoft, and Cisco (NASDAQ:CSCO) will be going out on massive shopping sprees, turning greenery that is earning a pittance in interest into accretive acquisitions. Well, in this particular case at least, Google would rather print out stock than dig into its coffers.

So let the conspiracy theorists whip up the questions that everyone is wondering:

  • Is Google conserving its greenbacks for an even bigger purchase?
  • Does Google feel that its stock is expensive at this point, making it ideal legal tender?

Google isn't about to tip its hand. For today at least, the AdMob rules.

What do you think should be Google's next purchase? Share your shopping list in the comment box below.