Social marketing is about word of mouth and community outreach. The same as it always was. The only difference is the tech.

Chik-Fil-A's Giveaways, Stunts Lead to Sales - from Advertising Age - News:
"Whether its through grass-roots marketing or giving away meals to customers, those stunts by Chick-Fil-A, a growing fast-food chain known for its lightly breaded chicken sandwiches, appear to be paying dividends. It's all part of a back-to-basics strategy that's also heavy on word of mouth and community outreach and it has Chick-Fil-A posting gains even as competitors with bigger ad budgets struggle with how much food they can offer for a dollar."