Any community ressources talk about the importance to encourage, empower and reward engaging contributions by giving members tools to build better communities and the opportunity to reinforce those behaviours..
Building reward solutions like badges, reactions, award systems, power users, curated content, featured users, gamification and boost visibility. Affiliate program can be handled via the paid membership side, to reward members by bringing new members.
I'm thinking about the importance of Tags in general that could suits for this purpose but also for many other situations too like searching a certain topic,...
Or like the actual groups, but with different attributions inside the community than the actual group role.