The other day I wrote about qualifying new members and the idea of making it harder for people to register on your community. A highly visible example of this is MetaFilter, a 15 year old, well known online community that has charged a one-time $5 membership fee for ten years. They also make you wait one week before you can create a new post. You can respond to posts by others, but not start your own.
A lot of community managers would be scared to even attempt such a thing. Clearly, it has worked for MetaFilter, or they wouldn’t have done it for so long.
I mentioned this in my initial post, but it bears repeating: a measure like this is meant to mitigate the challenges of success. If no one wants to join your community for free, then no one is going to want to join it for $5.