From http://www.investopedia.com/terms/p/ponzischeme.asp:
A Ponzi scheme is a fraudulent investing scam promising high rates of return with little risk to investors. The Ponzi scheme generates returns for older investors by acquiring new investors. This scam actually yields the promised returns to earlier investors, as long as there are more new investors. These schemes usually collapse on themselves when the new investments stop.
All else being equal, I don’t see a big difference between this definition and the high park rates being offered today. I do not condone this action.