Innovation in social commerce is coming thick and fast. Big business is experimenting with how social media, online media that supports social interaction and user contributions, can be used to facilitate and execute transactions.

One recent example is the leading European car manufacturer Renault.  At the top automotive event of the year in the Netherlands, the 2011 AutoRAI Amsterdam Motorshow, Renault offered all 250,000 visitors free RFID cards that could be linked to their Facebook profiles.  Visitors could then automatically ‘Like’ exhibited Renault model by simply swiping the card on information posts next to each car, and in doing so post a link to that car in their news feeds.

Yes, yes – it’s marketing not commerce per se – converting offline presence into online recognition and recommendations, but it is also a superbly smart ‘foot-in-the-door‘ sales technique.

The foot-in-the door sales technique is a powerful use of the social psychological principal of ‘consistency’ (see social psychology of social commerce) – our desire to be, and critically, be seen to be consistent in our thoughts and behaviour. It works like this.

If I make a big request upfront – “So you like the new Renault, then buy it!” then you’re likely to say no.  But if I make a small request, “So you like the new Renault, they why not like it on Facebook?, then you’re more likely to say yes – if indeed you  do ‘like’ it.  It sounds harmless, but my foot is now in the metaphorical door – and here’s the clever bit.

If I now go on to make the same big buy-the-car request, now or later, then whilst you’re still not likely to say yes, you are more likely to say yes.  Why? Because of the principal of consistency.  If we like something and can buy it, and have behaved publicly in a way that is consistent with liking it (especially to friends), but then don’t buy it following an opportunity to do, we feel psychological discomfort called cognitive dissonance.  It’s a light form of psychological torture – and is incredibly powerful, resulting in one high profile case with an entire estate of middle class home-owners voluntarily wrecking their own gardens.

Psychologically, the Facebook Like is deceptively powerful, perhaps too powerful.  Renault has just scratched the surface.  And as for opportunities, we believe that any start-up developing ‘swipe-to-like’ event marketing or in0store mobile rewards app, without all that tedious messing around with RFID cards, will become embarrassingly rich. Licence. To. Print. Money.