In a recent post, the first piece of cake and an earlier post, Tactics to help customers remember why they chose you I referred to Robert Cialdini's 6 principles of influence and persuasion. Here they are:
We feel obligated to return favours performed for us.
We look to experts to show us the way.
We want to act consistently with our commitments and values.
The less available the resource, the more we want it.
The more we like people, the more we want to say yes to them.
6. Social proof
We look to what others do to guide our behaviour.