>>31
100 people
Try 2 million. Even still, Esperanto can't become something if there are no early adopters. For an artificial language, Esperanto is amazingly successful, none other achieved anything close.
Even natural languages are backed up by a people, a nation, a military, and an economy as incentive. Esperanto has none of that and managed to become something, even if it's not much right now. It has survived centuries. Imagine what would happen if it hit a critical mass.
Is Esperanto perfect? No, of course not- but compared to natural languages its much better in so many ways. People will accept hundreds of irregularities in natural languages without blinking, and then laugh when they hear that Esperanto has some minor flaw that really has no practical effect on it's use.