08/15/2011 06:28 pm ET Updated Oct 15, 2011

Google's 5 Most Expensive Acquisitions To Date

Google announced on its blog Monday that it plans to purchase Motorola Mobility for $12.5 billion in cash. If the deal is approved by antitrust regulators, then it will go down in the books as Google's largest acquisition to-date.

Google's VP of Corporate Development David Lawee told Reuters in 2010 that the tech giant's agressive M&A strategy is "paying off huge." Big bets on young companies like Android and YouTube might have raised doubts when the deals were going down, but now most will agree that those have, thus far, turned out to be success stories

So will Google's latest buy prove to be a winner--or a costly, billion-dollar blunder? The purchase price of Motorola Mobility is more than four times the size of the DoubleClick deal, which until now was Google's largest acquisition. Further, skeptics doubt whether Google should even be buying a handset hardware maker to begin with, because the company's core business is in software technology, not low-margin manufacturing.

People have doubted Google's M&A activity before, but that's not to say it will stop them from continuing to make bold, aggressive bets. Google acquired over 20 companies in 2010 and more than one hundred to date.

Take a look at Google's five most expensive acquisitions (so far) below, and tell us in the comments whether you think the Motorola Mobility deal is the right move.