What you describe is not social marketing! Social marketing is a concept first explicated by Philip Kotler & Gerald Zaltman, Kellogg School of Management, Northwestern University, in 1971, to describe the application of commercial marketing principles to health, social and quality of life issues. (Cf. Kotler, P. and Zaltman, G. (1971) "Social marketing: An approach to planned social change. J of Marketing. Vol. 35, pp. 3-12.)
What you describe is better labeled "social media" or "consumer generated content."
Social marketing has been used around the globe by government and non-profit organizations to impact issues of societal well-being as diverse as breastfeeding, recycling and encouraging savings account.
Not a flash in the pan phenomenon, there are numerous college curricula; six-plus textbooks; an international listserve with over 1,000 members; a dedicated journal; three major US or international conferences; at least six major US firms; centers in Scotland, Canada, Poland and Australia; governmental centers in the UK and the US; a national excellence collaborative in the US, all dealing with social marketing
The impact of the social web extends well beyond marketing. Over time, we will see a sea-level change in how people in organizations work, communicate, make decisions. Traditional organizational structures don't stand up well to social networks.
One of the problems is that organizations don't do "communication" real well today. They struggle with exceptions, with speed, with people reaching out to whomever they like to get information or move something forward, with getting a response they don't like or didn't anticipate