Facebook’s recent partnership with PayPal is starting to take shape now that advertisers can use the online payments service to buy ads on the social network. The option is being rolled out today.

Facebook tapped the eBay-owned service to power payment for advertising and virtual goods on parts of the site in February. Users and marketers can choose PayPal as an option for purchasing ads and Facebook Credits, a system being tested in a small number of games and applications for buying virtual goods on the site.

At this time, Facebook is content to outsource payments services to its partners to help accelerate growth in virtual goods and self-serve advertising on the site, although it could develop its own payments system much later.

At the same time, PayPal is trying to broaden its reach this year by cultivating a developer community that can come up with unique applications. A deeper relationship with Facebook could open the door to all sorts of interesting social payment applications.