Internet entrepreneur Kevin Ryan on Friday predicted that Facebook is on its way to hitting $1 billion in gaming revenue this year.

In an interview with Reuters, Ryan — formerly the chief executive of ad giant DoubleClick — said his forecast includes revenue from Facebook Credits, now the mandatory in-game currency on the company’s site.

Gaming on Facebook is clearly big business: game developer Zynga filed for a $1 billion initial public offering, saying in its S-1 paperwork that its platform is almost completely dependent on Facebook.

A recent study from EMarketer found Facebook is poised to top Yahoo as the top display ad-selling company in the U.S.

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