We invited people that showed interest to meet the leadership first. Our main outreach was via the IRC (if anyone here remembers that). Quite a few came to visit, including a couple who came 4,000 km. They could not stay, but they went home rejoicing. Others did not respond so well.
A few stayed, even moving from interstate. The pastor passed away and most of those who joined us went their separate ways.
The ideal maximum for a home based fellowship is 30. It gets really hard to help everyone when it gets over that number. My wife and I have spent many hours with one woman who has deep issues to deal with. If the fellowship exceeds 30, its time to divide. I suppose that's why they are called cell groups. Some would say that it's more like the leaders want to put you in prison.
The pyramid structure of the modern church is a hangover from Roman Catholicism. Structure has value, but the church is a body, not a one band. So we should endeavour to follow the Biblical pattern, "What then shall we say, brothers? When you come together, everyone has a psalm or a teaching, a revelation, a tongue, or an interpretation. All of these must be done to build up the church." (1 Corinthians 14:26)
If you want to know why the church is so weak and insipid, you have your answer.
My apologies for the rant. It's not exactly on topic. Hopefully it helps.