Facebook announced their own ad network today called Facebook Audience Network. It serves ads similar to Admob but will be highly targeted as it uses profile details of the app user's Facebook account. Ad types include banner, interstitial, full-screen ads.
Please create a wrapper so that we can use FB ads in B4A.
Finally MoPub library is updated with new MoPub SDK v2.3 (17 July 2014) , new ad networks (overall there is support of more than 20 ad networks for now including Facebook (banners & interstitials)) , simple integration guide and general help how to use MoPub. Hope it is simple guide