Why not create a private blog for just 10 specific people? Or a social network just for the 20 greatest minds in psychology?
Why do we need as many people as possible?
Why not create a community with the specific goal of bringing your top 5 distributors, customers and employees together to create a code of best practice?
Why not target the specific people you need for a specific outcome?
If your community is an open one, perhaps it’s time to ask why?