That's how ponzi schemes work. They pay reliably until they collapse. If you are in early enough and manage to get out before the collapse, they can be profitable for the participants. Highly risky though, and the majority will lose all of their investment. And, they're obviously very illegal pretty much everywhere. Those few lucky participants who end up winning could be sued by the suckers for their losses. Also, anyone promoting a ponzi fraud could be considered a co-conspirator.