Social networking website Facebook is dipping into the brick-and-mortar world by selling gift cards at retailer Target that can be used toward purchasing virtual products for games hosted on the site.

Facebook Credits will be available in Target stores beginning September 5 in increments of $15, $25 and $50.

Social games that can be played for free are some of the most popular activities on Facebook, which has about 500 million members worldwide. Games such as Zynga's FarmVille invite users to interact by buying imaginary land, growing crops and expanding their farms. The games generate revenue through the sale of virtual goods or services.

Social games have generated a lot of heat among companies seeking to tap into a growing market. The Walt Disney Co acquired game start-up company Playdom Inc for $563.2 million in late July, and Google Inc is seeking to kick-start an effort with social games.

(Reporting by Jennifer Saba, editing by Maureen Bavdek)