Do you know any examples of niche networks being built using NING & later sold?

I know someone who is pursuing such a plan, and I'm curious if it is a viable exit strategy. The only thing I can find on Google is a couple of specialty job groups that were set up on Ning that were later sold to a different group manager. Any ideas? (vBulletin type sites aren't really the same thing since that is self hosted & the software is easily changeable to another provider whereas I am not sure the same can be said about Ning).