I prefer the SomethingAwful forum model: start out free, start charging a one-time $10 fee for new memberships, and then be liberal about banning people (who ca

I prefer the SomethingAwful forum model: start out free, start charging a one-time $10 fee for new memberships, and then be liberal about banning people (who can pay another $10 to become unbanned). There are other premium options available for other one-time charges. Being able to moderate in a way that costs someone $10 can really help reign in the more destructive members of the community. There are people who keep resubscribing, but they subsidize the site for everyone else as they get banned over and over.