What do the founders of online communities owe to their users?

We discuss the organisation of internet communities, focusing on what we call the principle of "bait and switch": founders of internet communities often find it advantageous to recruit members by promising inducements which are later not honoured. We look at some of the dilemmas and ways of attempting to resolve them through two paradigmatic examples, Wikispaces and Wordpress. Our analysis is to a large extent motivated by the demands of CALLector, a university-centred social network we are in the process of establishing. We consider the question of what ethical standards are imposed on universities engaged in this type of activity.