Well, that describes the membership accurately enough, but there the rand cult as a sociological phenomeon -- characterized by rand's hold on her followers and their dog-like obedience to her every whim (including sharing her eccentric literary and musical tastes). The right-wing libertarian Murray Rothbard made a good stab at describing the group dynamics of the randians. See: http://www.lewrockwell.com/rothbard/rothbard23.html
Also, there is interesting material in Jeff Walker's book The Ayn Rand Cult (which I've only glanced at -- but the parts I read seemed very well argued.)