1) A phrase used by idiots for any type of scam.
2) A specific type of scam. The operator (often from nigeria) of the scam promises "investors" that their money will be doubled in a certain number of days. The operator depends on the money provided by later investors to pay off his obligations to the earlier investors. This turns out splendidly for the early investors (assuming that it takes off), but later investors get the short end of the stick, as no more people are enrolling. At this point, the operator usually takes the money he has left and runs. This generally sucks for the later investors. Not that I care, because you have to be a total dumbass to enroll in a ponzi scheme anyhow.
1) Bill: these people are trying to make me think I can get a free iPod for answering a survey. Looks like a ponzi scheme to me.
Me: Bill, you dumbass. That's not a ponzi scheme.
2) Just great. I just got another one of those get-rich-quick spams. I'm amazed that anyone buys into ponzi schemes.
see social security.
A scam involving paying off money to old investors with new investors' money. Eventally the last group of people paying into the scam never get their money back.
Bill: Hey Will, what's this line on my paycheck that says "Social security"?
Will: It's the government's ponzi scheme. You'll never see that money again.