When you have billions of dollars in your piggy bank, you can go on a big shopping spree and hoover up some decent technology.

According to BerkeryNoyes, an investment bank, there were 4,151 mergers and acquisitions in the online/mobile market between 2010 and the first half of 2012, and the biggest shopper was Google, which had 49 transactions.

Did you know that there’s a Wikipedia page dedicated to the list of mergers and acquisitions by Google? According to the page, which lists 119 transactions from February 2001 through October 2012, the largest was of course Motorola Mobility. This deal happened in August 2011, and cost US$12.5 billion.

That’s a lot of piggy banks.

While Google has a justly deserved reputation as a hotbed of innovation, it’s clear that the company’s success is due just as much to smart shopping as pure technical prowess. The Motorola deal, of course, gave Google a huge patent portfolio, but look at who else Google has bought lately: The Dealmap daily deal service, the Zagat restaurant reviews, the Meebo instant messaging platform, Apture instantaneous search, RightsFlow digital-rights management, Wildfire social-media marketing, the Quickoffice productivity suite, Frommer’s travel guides… The incredibly diverse list goes on and on.

Google’s not alone in pursuing checkbook innovation (as well as checkbook market share). Every big tech company makes acquisitions, some huge, some tiny. Think about Apple, CA, Facebook, IBM, Microsoft or Oracle.

In some cases, these firms are buying patents; in others, source code or customer lists to milk for upgrades or migrations. Some of these deals buy out competitors (which are then shut down); some grab companies to settle lawsuits (by buying the opposing party); sometimes it’s a way to recruit some technology talent. Think of, for example, Apple’s buying Steve Jobs’ NeXT Computer in 1996, or Microsoft buying Ray Ozzie’s Groove Networks in 2005.

At these companies, the best and brightest computer scientists refine algorithms, tune source code, conduct basic research and invent the future. Their financial success and market position certainly owe a lot to prowess with an IDE. The firms, though, deserve as much credit for their deal savvy—buying the tech just as much as inventing it.

Alan Zeichick is editorial director of SD Times. Read his blog at ztrek.blogspot.com.