With dozens of social marketing venues for its divisions and subdivisions, General Electric still retains central oversight, largely through its use of analytics. As new platforms rise and fall, Paul Marcum, director of global digital marketing and programming at GE, keeps a close watch, game to test-drive their effectiveness. But he's just as willing to move on if the venue doesn't attract the desired audience. For instance, the company let its Foursquare presence go when it realized the platform was not a match for GE's marketing needs.