Explaining the differences should be fairly easy and straight forward. Prospective members don't need to know about the multiple tiers as they don't qualify for at least a year (if ever). We are a group that collaborates on Sage 100 technical issues though we are trying to grow the groups to bring in more CRM, Sage 100 and other types of contributions. $500 for the initial company member, 250 for each additional. We do offer one or two conferences per year which is a great way to meet the other members and develop your network. Keep it simple, no need to mention the inner circle to prospects.
As far as optimal number, I don't know of one but I don't think we are there yet. We are experiencing growing pains regarding the distinction between vendors and resellers, consultants and marketing/sales types. We aren't at the critical mass of membership where we can support a full time employee. And before that happens, we have to decide what we want to be when we mature. If we start seeing an increase in large company membership, their wants and ends are very different (as the ITA recognizes). I think if we grow the business, this will be an even bigger issue to tackle. But more importantly, what will the state of Sage 100 be in five years?? We had an interesting meeting at the ITA regarding Intact and netsuite. I don't see many of the existing membership taking those products on. As the senior partner said, give me 8 more years to ride this to retirement.......