Google has confirmed its purchase of San Francisco-based Adscape Media in a push into in-game advertising.

The long-anticipated deal – believed to be worth around $23m – will see the search giant entering a market that’s expected to grow massively over the next few years.

It follows rival Microsoft’s $200m to $400m acquisition of in-game ad provider Massive last year.

Adscape, which can place static or dynamic advertising inside PC, console and mobile games, as well as offering demographic and geographic targeting, has yet to strike a deal with a game publisher.

Massive, meanwhile, has agreements in place with UbiSoft Entertainment, THQ and Take-Two Interactive Software.

However, Red Herring reports that the move will give Google access to a patent portfolio that could potentially create some headaches for its rival.

Adscape’s most interesting patent, apparently, was filed in 2002 and “is for a complex gaming system that sounds similar to Microsoft’s Xbox Live service”.

The Yankee Group predicts that the video game ad market will grow from $56m in 2005 to $732m in 2010 – not large when compared to Google’s PPC revenues but potentially a nice earner.

In a written Q&A on its site, Google said it would start testing how to implement the ads, but said it didn’t know whether they would be integrated into game content or take the form of AdSense-like contextual text ads.

“Over the past few years, the video game experience has become richer and more interactive. We think this rich environment is a perfect medium to deliver relevant, targeted advertising that ultimately benefits the user, the video game publisher and the advertiser.”

In separate news, Google has also announced it has acquired Trendalyzer from GapMinder, software that makes easy-to-understand animated presentations out of complex socio-economic data.

The product will now be given away for free. We will be watching to see whether Google plans to integrate Trendalyzer with its Analytics reports.