Strong communities usually exhibit these 5 features:
1) Boundaries. Great online communities have boundaries. They split the insiders from the outsiders. The boundary might be something members have done, something members are or something members want to be.
2) Purpose. Great communities have a purpose members strongly believe in. It might be to elect a new president of the USA or share the latest film news. It’s not the strength of the purpose that’s important, it’s how fiercely members believe in the purpose.
3) Communication. Great communities communicate, a lot. They communicate both one to one and many to many. Great communities have a communication platform. It might be a local newsletter or it might be a leader educating the group. Create a platform for both many to many and central communications.
4) History. Great communities have history. It’s documented and available for everyone to read. The history lists the achievements and contributions by members.
5) Emotions. Great communities oscillate at the same emotional frequency. They’re happy, sad, angry together. They share the same emotions at similar times.
If your community isn't as strong as you like, focus on developing these aspects. Make tougher boundaries, test belief in purpose, stimulate more communication, document and broaden the history or try more emotional appeals.