Charging a community membership fee is a unique boundary. It scares 99% of people away.
But that committed 1% might be just what you need.
They expect value. They will participate to get it. They will consume content, contribute ideas and they have a stake in the community being a success (they don’t want to lose their investment). Most importantly, they will appreciate the community more.
This model works better when you don’t let everyone join. Have other preconditions, more boundaries, to pass before a member is allowed to pay. Perhaps a blog with 650 subscribers? Or a column in a monthly magazine? A published book?
This works best for elite communities, ‘official’ communities, communities with stunning content and communities with unique benefits benefits (like NUS).
You should also know the total sum of money members have invested into the community so far. Many would pay £3 a month to join a community worth £940,000.