Facebook is officially taking the first steps to becoming a global ad network today. The company is running tests on ads outside of the Facebook experience for the first time.

The company confirmed the step publicly. mobile-games-3“We are running a small test to explore showing Facebook ads in third-party mobile apps,” Facebook engineer Sriram Krishnan said in a short post on the Facebook developer blog. “In this test, we’ll be extending Facebook’s rich targeting to improve the relevancy of the ads people see, provide even greater reach for Facebook advertisers, and help developers better monetize their apps.”

Facebook is one of VentureBeat’s top 10 mobile ad networks, as detailed in our recent report. More info here, and you can sign up to buy it here.

This move has been rumored and anticipated for months if not years, and Facebook has dabbled in external ads before (using external ad networks to complete the purchases), but in this test, Facebook itself is directly interfacing with ad buyers and publishers.

Clearly, Facebook has a lot to offer advertisers who want to place ads beyond the walls of its social service. With extremely deep targeting capability and huge amounts of data about users, Facebook ads can be tightly targeted and have been returning increasing ROI and clickthrough rates in recent months.

Facebook says the new ads will help mobile developers monetize their apps and that this is a solution to the lag between amount of time spent on mobile, which is skyrocketing, and the amount of money collected via advertising, which is merely growing.

Don’t hold your breath if you’ve been hoping to get in on the test, however.

Only a small number of advertisers and partners are involved in the current program, Krishnan said, and Facebook is not currently accepting any new parties. That essentially means: We’re working out the bugs, we’re building the advertiser ROI case, and we’ll release it when — and if — everything works well.

You can, however, be one of the first ones notified, simply by entering your information here.