Community teardowns / by model
Busiest rooms
Three or more posts per member, 500 members or more. Activity as the product.
At least three posts for every member, in communities of 500 or more. Most communities are read far more than they are posted in, so a room where the average member has posted three times is unusual, and it is the single strongest sign that people are getting something from being there.
Worth studying for format rather than price. The busiest rooms are almost always built around a prompt to post: a daily check-in, a weekly critique thread, a challenge with a public log.
9 communities
Idea Finder
Seen enough to know what you would build?
Six questions and you get an opportunity report for it: the gap in your category, what comparable communities charge, and where to build it.