When it comes to search engine technology, there have not been many breakthroughs over the years. If anything, the main one continues to be Google's (GOOG) PageRank system, which is an algorithm that lists search results based on popularity.

But Google has a lot at stake since most of its revenues and profits come from search. So the company is certainly attentive to maintaining its lead. This, of course, means engaging in a variety of acquisitions. The latest one is for Like.com. The price tag was not disclosed but the buzz is that it was as much as $100 million.

Google, Inc. (NASDAQ: GOOG) Has slowed down its acquisition juggernaut in the last six months. No small or medium companies have been purchased as the company hoards cash to add to its $16 billion pile. Does Google really need anything right now? Not really -- the advertising slowdown has affected it but the company is not hurting. If anything, more restrictive ad dollars are flowing into the internet due to its highly-targeted nature. Google commands this market with an iron fist.

Google Inc. (NASDAQ: GOOG)'s recent spate of acquisitions is nothing to sneeze at -- the web search giant (and internet advertising colossus) seems to be getting bigger in size, breadth and depth by the second, to the fear of Microsoft Corp. (NASDAQ: MSFT), Yahoo! Inc. (NASDAQ: YHOO) and many established industries from newspaper to radio. Google's intention, as I've said many times, is to become the largest advertising network on the planet, and the company is not leaving a single stone unturned in its quest to get there. With the billions Google has in the bank, along with marketable securities that it has ready to spend, the acquisition trail has not been light to the company. In fact, it's acquiring companies left and right -- some are high-profile deals while others are significant but small.

While not all of Google's acquisitions directly point to its goal of an all-powerful advertising behemoth, there are peripheral industries that produce acquisitions that are meant to help Google keep its stranglehold on the web browser and access to it where it can display its advertising, help connect buyers and sellers and take its traditional cut of the transaction. In fact, two of Google's largest acquisitions to date -- YouTube and DoubleClick -- are directly related to allowing the company to maintain its advertising grip while it expands its tentacles into any area that it can to allow for sustainable control over the face of advertising. One thing still slips past many: Google still makes virtually all of its money from web advertising. Make no mistake: protecting that is Google's #1 priority.

While it does that, though, Google's 11 company or technology purchases in the last year have helped the company fill gaps in its product portfolio for customers from offering web-based documents to integrating as many neat features into Google Earth as possible (which still makes a pittance in "pro" subscriptions). Interestingly, though, competitor Microsoft has made about 13 acquisitions during the same time period, with the most recent being aQuantive (a pure-play response to Google's huge advertising threat on the web).