Match your community platform to it’s size.
A mailing list is brilliant for up to 40 members. After that you need something bigger, like a forum or Facebook group.
When you have a thriving forum you probably want something better, like editorial content about the community, game mechanic features and better profiles.
Creating a full fledged community site is a bad idea for 40 members. Remarkably, most companies create a site for 0 members (or 10,000 estimated members).
Match your growth and spending to the size of the community. Don’t try to do too much too soon.