Hey, I'm gonna do you a favor and quote the wiki for you:
In a Ponzi Scheme, the founders persuade investors that theyll profit. Bitcoin does not make such a guarantee. There is no central entity, just individuals building an economy.
A ponzi scheme is a zero sum game. Early adopters can only profit at the expense of late adopters. Bitcoin has possible win-win outcomes. Early adopters profit from the rise in value. Late adopters, and indeed, society as a whole, benefit from the usefulness of a stable, fast, inexpensive, and widely accepted p2p currency.
The fact that early adopters benefit more doesn't alone make anything a Ponzi scheme. All good investments in successful companies have this quality.
Now as the definition goes,
In a Ponzi Scheme, the founders persuade investors that theyll profit.
no one is telling any one to invest in Bitcoins.
Also a small warning, don't go around to forums and start slandering them when you haven't even done research!!!!This thread made me laugh

Can't tell if serious. You do know who Fonzi is, right? Are you familiar with the origin of the phrase "jumped the shark"?