PBA — This is not a Ponzi scheme at all — did you read the ad clearly? The point is that these families are committing to pay very high shadchanus if someone makes a shidduch for their child, and the money is “held in escrow” so to speak by Nasi. Nasi is not paying “rewards” to anyone. They are simply compiling a list of families willing to pay these super high rates, and guaranteeing that the money will be payed by holding it in advance. Each person is paying the exact amount for themselves — not for the people before them, and if you chose to drop out (for example you get engaged via a different method!), they simply give you back your own money that they were holding (not clear if you also get back your $500 processing fee or not!).
I’m not saying I like the sound of this — I actually don’t — but your analysis makes no sense.