Larry Osborne argues that it's better to have a smaller "sticky" church were people stay around than a larger church with lots of people coming for a while and then leaving. His central idea for a "sticky" church is "sermon-based small groups." It's very much common sense, generally people feel more comfortable learning about God and sharing their lives in smaller groups. He advocates keeping groups together instead of redividing them, because dynamics matter and following the sermon series because it helps people learn more about the Bible by discussing the same passage they've heard on Sunday. He's also an advocate of simple church, were small groups are prioritized over various alternative programs. Although with all this it's good to keep in mind that this is just an argument for one idea for helping churches work, not the endpoint of Christian discipleship or even the secret to church growth!