Leading and engaging

I'm struggling with how to keep my participants engaged. Everyone seems really excited about the project and eager to help me, but they also have their own lives to be concerned with and distracted by. I don't want them to start feeling annoyed with me and my persistence, but I also need to keep reminding them to check the blog and respond. So far, it's been hard to get them to read and comment on each other's posts too. I'm hoping maybe the first face-to-face meeting with everyone will change a lot of that...providing most of them come. I have a total of 5 participants now and am wondering if I should try to add a couple more. It's probably best to do that early on rather than wait until the group feels too comfortable with one another to accept new people.