Start a group too early and you will find yourself trying to build two communities instead of one.
Early-stage communities are fragile.
You need to build up enough participation to reach a critical mass of activity. Launching a new group risks splitting activity into two areas – both of which you now need to grow and support.
It’s common to try and turn a popular topic into a group. This means conversations that would previously have appeared on the landing page now appear in a group. However, the hiding discussion behind an extra click makes the community look a lot less active.
There are three reasons to launch a group in your community.
1) When there is an overwhelming demand for one. Members might want privacy, exclusivity, or a place to have high-signal conversations with a specific group of people. If you’re not sure if this demand exists, it doesn’t.
2) When a topic is overwhelming the community. Sometimes a single topic (or group of members) is/are overwhelming the community landing page. Launching a group makes sense here.
3) When you have a specific goal. This is a risky top-down approach. Far too many communities have dozens, even hundreds, of empty groups that they created for members who were never asking for them. The good examples here are newcomer groups and MVP/Insider groups. I’d be cautious about creating groups outside of this.
As a general rule, you shouldn’t think about launching groups until you have a few hundred active participants in your community. And even then there should be an overwhelming demand for that group.