Interactions are the lifeblood of communities.
Without interactions, members can't build relationships, a community culture can't be develop, a social hierarchy can't be established. Without interactions, you have nothing. Without interactions, people wont keep coming back nor invite others to join and participate.
You can build a lot on top of interactions, but you can't build anything without them.
You need to directly stimulate interactions. Most community plans would benefit by stripping away everything in your plan/strategy that doesn't directly stimulate interactions (interactions, not just visits). Forget the branding, design, content, promotion, monetization.
You will be left with a relatively small list of tasks which will include:
- Helping newcomers make their first contributions.
- Initiating interesting discussions.
- Ensuring every discussion gets a reply.
- Hosting events/activities members can participate in.
- Inviting members to participate in relevant discussions.
- Introducing members to each other.
These are exactly the tasks most community managers should focus on.
Don't hope for interactions to just happen. They're too important to be left to chance. Work hard to directly stimulate interactions in your community.