Facebook said today that application developers can now apply to test out its virtual currency platform, an aggressive move that places pressure on virtual currency companies such as Offerpal and Zong. Third-party virtual currency companies have made millions of dollars over the years through the sale of virtual goods on Facebook social gaming applications.

The social network also said it’s rolling out a new feature that makes it easier for application developers to advertise to new users based on what applications they’ve used in the past. The same feature also lets developers advertise to current users as a way to encourage repeat visits to their applications.