On-line tools or norms. Hosts are like a party. Those facilities need to meet people, remove fights into the hall, and keep conversations going. They naturally evolve or you can train people to do it. Cyberian is someone whose job are knowledge management, and also someone who lives in the community.
Idle talk is social glue.
If it is not fun people will not contribute. You cannot step on fun if people start having it. People who make friends in those informal settings are more likely to have useful knowledge in a more formal setting. Also learning is a social activity. When people are not compelled to participate, they do it voluntarily.