Maybe until you get as many people as you like and a stable group you could just have topics to discuss informally rather than each person having to work so hard to participate? I think a lot of people go to things, become part of things to listen and learn rather than have to "work" after working for their living. I would have "contests" or sponsor "experiments" (using specific self-help tools) and make it a bit fun too, see if more people didn't come because they enjoyed it rather than just coming to listen to a "lecture", thinking they might have to lecture next.