RealNetwork’s GameHouse unit is testing the use of Facebook Credits on GameHouse.com, which could open up a option for websites by allowing them to use the social media site’s tool to process payments for virtual goods.

The test is being kicked off with GameHouse’s Collapse! Blast and UNO Boost games.

Facebook’s virtual currency is used by game developers Zynga and PopCap Games as a way to pay for virtual goods on Facebook. And the pilot program with GameHouse will allow the RealNetworks unit to use Facebook’s payment platform on GameHouse’s website.

GameHouse has only accepted payments through credit card and PayPal, and Facebook Credits gives game users on GameHouse’s website another payment option.

If Facebook does open the door to allow other websites use Facebook Credits to sell virtual goods or buy games, it could give Facebook a 30 percent share of sales, in exchange for giving GameHouse and other game sites a more convenient way to process transactions, according to Inside Facebook.

Facebook said is “gathering early developer feedback" to determine if it will expand the program beyond Facebook to other websites.

The test drive with Facebook Credits comes at a time when casual games developer GameHouse is struggling to gain traction against competitors such Zynga and PopCap Games.

GameHouse is one of the top 20 game makers on Facebook, which has become an important platform for casual game makers to land more players and sell more virtual game accessory goodies that are important parts of a game’s revenue stream.

But GameHouse has had seen its workforce fluctuate, while RealNetworks ponders the unit’s future, according to The Wall Street Journal’s All Things D blog.