I learned about ning.com from Steve Garflied and Chris Brogan, and then I saw that Steve of JetSet was using it. and it if was robust enought for Steve and Zadi, that was a definite plus.
then a tech friend of mine who is well versed in these things gave a big plug for Ning. then David Sklar of Ning came to BKLN 2.0, my monthly meetup http:// web.meetup.com/54/ and talked to us about ning.com, and i liked that he was nearby for help. my recent emails to their help desk have been answered within a day, and they have a ning site just for ning creators to help each other. i like how one can customize the look, if you know CSS you can do all sorts of things to it. right now i'm working on some URL domain mapping issues, then The Greenhouse www.thegreenhouse.gardenfork.tv will go live and i will announce here.