So a forum for google groups of people you know or may not? I guess I am just trying to understand the use case as well as revenue model.
As for peer group I see it in 2 ways: 1. You know the people but don't have a weekly/etc. meeting 2. People who you don't know but working on building a product/company
Another thought would be more of a mastermind group. Limit it to 10 people or something and focus on weekly meetings to encourage everyone to get things done. What did you do last week, what are you planning to accomplish, etc.
Just a thought