Charles Ponzi was arguably the best-known fraudster in US history. Although he did not invent it, he gave his name to a classic type of scam - effectively robbing Peter to pay Paul.

A high return would be promised to one set of investors and for a time, it would be paid, but only by exploiting the contributions of new investors. A chain letter works on the same principle. In the end, the supply of new mugs is bound to run out and the scheme is sure to collapse.