NEW YORK (AdAge.com) -- The "Big Idea" has long been the traditional core of ad campaign organization but does it really work that well in the new age of social marketing? That was the issue raised at the recent 4As' strategic planning session by Mark Earls. The author and marketing guru discussed new insights about the behavior of human communities and warned marketers and their agencies not to assume that a single creative concept will work effectively across a wildly diverse and unpredictably fluid social environment.