By only a dozen people signing up. That certainly shows the rapid progress you've made there over the past few months.
I thought the same thing. That's not a bad number (and your final number is even better).
We've had summer short series events with way fewer people. I think you're doing a fantastic job.
As long as the disappointment does not discourage you from continuing on with this VERY successful O-venture, it's not necessarily a bad thing. :-)