I'm no expert, but I believe the idea of getting celebrities to join isn't to get their money (although I'm sure they freely donate it). I think the idea was to seduce celebrities by automatically promoting them to the higher "levels" of the religion. This, inturn, would attract your average person hoping for some sort of comraderie with so-called celebrities, although your average person would have to pay along the line to get there (and most likely wouldn't ever reach it).