There have been 12 posts on the Believer's board by a total of 6 people so far this year.
No FE movement in schools. No textbook. No map. No usefulness. No evidence. No astronomer, ship captain (or sailor, actually), or geographer, or ham radio operator, or gps engineer, or pilot, or anyone whose daily life involves the shape of the earth has come out. If some know and are under physical threat from all powerful secret organisations, why don't they come after FES? AnyFEs here ever get threatened by NASA? If not, that is really pathetic, FES is not a threat to them.
Although my advice may not be appreciated, if you had a flat map with constant scale and accurate distances everywhere, FE would take off like a rocket. Yet no FE ever seems to present one. I say that is the key, and FE should focus on that. Without a map, you are not legit, not real, not credible, not believable.
Why worry about the number of believers, why not first produce scientifically accurate, well proven, and well presented videos, a map, a ring laser gyroscope that does not precess 15 degrees/hr, and a map. Then FE will go viral among the general population instead of just the conspiracy addicts.
If you want FE to take off, you need a map. Have you considered devoting all your FE efforts to a map and not posting until you have it?