The Audience Network enables advertisers to extend the scale of their Facebook ad campaigns beyond Facebook and into mobile apps that have partnered with Facebook to display ads. Although these ads run outside of Facebook, they can leverage all the targeting, measurement, and other tools for advertisers.
Audience network is available globally (except for Brazil). It is limited to mobile app install ads, mobile app engagement ads, website conversion ads, and website click ads. The ads are available in three creative formats: a 320 x 50 banner, full-screen interstitials, and native ads that fit the look and feel of the app they are placed in. Advertisers do not have the ability to edit the layout of Audience Network ads.