Understanding why people behave the way they do, and designing interventions and communications to elicit new, more positive behaviours is an established discipline - but using social media as part of the mix is relatively new.
I’m convinced it has the potential to be hugely effective, because our behaviour is often defined by our interpersonal relationships and our perception of social norms - both things that are an inherent part of the social web.
From a research perspective, the massive volume of personal and conversation data we publish to the web everyday also gives us a gold mine of information that can help us understand individual’s online behaviours and attitudes - more quickly and at a lower cost than traditional research methods.