Social networking site Facebook has begun testing its much-anticipated virtual currency payments system with third party application GroupCard.
Users who want to buy a GroupCard e-card through the company's app are now offered the option of clicking on a "Pay with Facebook" button.
They then pay with their credits, worth 10 cents each. The currency can be bought - with a credit card - from the Facebook gift shop.
The testing comes after Facebook updated its payments terms and conditions on Wednesday to pave the way for the platform.
Facebook will take a cut of every transaction, potentially providing it with a significant revenue stream. The site currently has around 200 million users and more than 52,000 applications in its directory.
Letting customers make purchases with credits enables merchants to sell content for small amounts without being hit by prohibitive credit card transaction fees.
The currency could also break out of Facebook, being used for micropayments on a range of Web sites such as magazines and newspapers.
Earlier this month it emerged that the Wall Street Journal is planning to introduce micropayments for access to articles on its Web site later this year.