I would try to answer even I'm not the thread starter or that I use this option, but could use such a feature.
I have a forum for disabled people. People are very timid, shy and reticent. It is very difficult to get any action from them, even register, if they can not be motivated by fx many users, a lot of info in forums, where they can feel safe and 'hidden' them self. None of them starts anything by themself, be the first and be constantly motivated started with some posts by them self.
I try the best I have learn to motivate them - but for me, this could be a nice functions. Fx generate x users, with the same email and password.