Facebook is once again accepting applications for its Preferred Marketing Developer (PMD) Program after temporarily closing the ad program to new candidates last month pending updated requirements.

The social network on Monday announced PMD applicants must now be referred by a Facebook employee or a current PMD vendor. Facebook also set additional requirements for earning badges for qualification across the four areas of expertise covered by its partners: ads, apps, insights and pages.

"These new requirements will facilitate the implementation of features such as boosting Page content in news feed, accessing Open Graph insights for app developers or taking a holistic view on pages insights across owned, paid and earned media," stated a post on Facebook Studio today.

All PMDs and candidates, for example, must be be able to advise marketers on ad spending to amplify word of mouth and ensure success on the platform. That means being able to show successful campaigns already run on Facebook, how you would pitch Facebook with clients, and “how closely you follow Facebook Marketing channels such as official page updates, micro sites or Webinars.”

In lieu of a referral by a Facebook employee, an applicant will need to get a referral from a PMD with an Ads badge. That underscores Facebook’s emphasis on having partners with experience developing paid as well as earned and owned media strategies.

It also fits with the company's broader efforts in the last year to ramp up advertising in connection with going public.

The new requirements go into effect immediately for PMD applicants, while existing program partners will have until October to comply.