When your community is a destination members need to visit, rather than something that visits them, you have to work much harder. It’s much easier to participate in a community when participating is embedded in something you already do.
This is why mailing lists work so well. You get a discussion e-mail to reply to. You have to make a decision to delete it or respond. Quite often you respond. You can’t ignore it. You have to make a decision.
Compare this with communities hosted outside of our daily routines. Communities that are based on destination websites, in which members have to remember to visit, struggle much more for participation.
This isn’t to say that every community should be based upon e-mails, Twitter updates, Facebook notifications and everything else of our daily routines. Larger, more active, communities would overwhelm the common user.
If you’re just starting out and suspect activity might be an issue, bring your online community into the daily habits of members. When you’re ready to grow and feel your community has become a habit in itself you can move somewhere bigger.
(Likewise struggling communities might want to invite their most active members into a mailing list to rejuvenate activity before moving back).