Soviet
Hello! Now I'll tell you the basic principles of how not to fall into a pyramid scheme, but first I will briefly planted what it is: a pyramid scheme gets its name from the fact that if you draw it primitive scheme you will get a pyramid on top of which will be the founder of, and underneath all the participants. Those who still remember the Soviet times probably just remember that from time to time in the country were waves "Post" the pyramids – the man came asking for the return address to send an email with a certain amount and then send yourself the same letter five friends. The idea was that if, in a letter sent to you asking you to to send back 5 rubles, you asked for five rubles in five people is 25 rubles, and if you count the cost of mailing letters and sending her five rubles it turns out that you would get about 19 of net profit, but you must remember to Soviet times it was a lot of money. So what's the catch you ask? And here's the man who organized the letter sent pyramid clearly not dozens, but thousands and tens of thousands of others. That is, if suggest that he sent letters to 1,000, he received 5,000 rubles, and this at a time when the salary of 100 rubles a month was considered high. Now I think you all clear that having a gigantic amount of people "went underground", but then was another trick: the pyramid was not stopped, but continued to work in a geometric progression.