Facebook does not currently support the subscription model. Instead, developers of apps on its platform make money when users buy virtual goods. They do that either in a currency unique to the app or using Facebook credits.

By the end of the year, real currency will be accepted for subscriptions, and in-app payments will have to rely on in-app currencies. Facebook explained that Credits launched at a time when few apps had their own ersatz currencies. Now, many do, alleviating the need for a "platform-wide virtual currency," the blog post said.

The announcement emphasized the benefits for developers, including the ability to "price the same item differently on a market-by-market basis."

"We anticipate that features built on local currency, like subscriptions and multiple currency price points, will also help developers monetize more effectively," the company in its materials for developers.

The new model is already being used by some developers, including Kixeye and Zynga, in a private beta test.