Yes, the product is open source, and there are a handful of churches using (or trying to use) the self-hosted option. I don't have good numbers on that, but I think you're right -- more churches are paying me to host than doing it themselves.

The City, and just recently, The Table are both bigger competitors.

...so you're saying, reduce the feature set and make the smaller product more focused? That's a good idea; thanks for the advice!