NEW YORK (AdAge.com) -- The $4 billion sale of Burger King to 3G Capital Management this week doesn't mean flip for McDonald's firmer-than-ever position as the No. 1 burger chain. But it does present an opportunity to steal back at least some of the share ceded in the past couple of years to the Golden Arches as well as fast-feeders like Wendy's, Subway and Domino's.