Facebook has decertified more than half the seat holders on its Facebook Exchange (FBX) as part of a revamp of its marketing partner program, unveiled Tuesday. Among the partners no longer badge-certified to buy on FBX are some very big ad platform players, including Adobe, Advertising.com (AOL), Rocket Fuel, IgnitionOne and Dotomi/Conversant (Epsilon). In total, the number of publicly listed FBX