Carey Nieuwhof has a list of 8 Reasons Most Churches Never Break the 200 Attendance Mark.
(In the PC(USA), over half of congregations have fewer than 100 members. Plus, anecdotal reports suggest that attendance is routinely smaller than membership. For example, the UMC has a membership of 7 million, but weekly worship attendance is less than 3 million.)
I think church growth is a lot like tithing. If they ask at all, people ask how little God will settle for, instead of how much will God be delighted with.