 If you get a pitch by phone, mail, or email that makes incredible financial promises, such as high returns with a low risk, you might ask yourself, how is this possible? In most cases, it's not. Postal inspectors say investment opportunities or get-rich-quick schemes are a favorite of fraudsters. Whether they sell bogus securities or commodities, oil wells or gold coins, these fraudulent promoters try to get you to invest your money and lots of it.