Facebook's virtual currency, "Facebook Credits," is getting very close to its full launch: a post on the Facebook developer blog explains some of the full terms of the system and what developers can expect as the currency continues to roll out slowly.

"Today more than 500,000 applications exist on Facebook, and the virtual goods within those applications (particularly games) have become an increasingly valuable part of the user experience," the post explained. "By providing a single, cross-application currency, our goal is to [make] transactions simpler for users, leading to a higher conversion rate for developers. Specifically, our early testing has shown that users paying with Facebook Credits are significantly more likely to complete a purchase than the average Facebook user."

Developers will need to believe in that incentive: Facebook plans to take a full 30 percent cut of Credits transactions. Some developers have already denounced that as too expensive. Facebook will have to give them the hard sell in order to win them over, as many third-party currency start-ups have already flooded the developer platform, and there are consequently lots of other options out there.

More: http://news.cnet.com/8301-13577_3-10460201-36.html