Critics of multilevel marketing businesses like Amway and Herbalife make bold claims. Bill Ackman, an institutional investment manager who tried to take down Herbalife, once said of the company, which purportedly sells nutritional supplements, “the customers are fictitious, the business opportunity is a scam.” MLMs are called pyramid schemes, their sellers likened to the snake-oil salesman of yore. The critics’ line goes that these companies have tricked their customers into thinking they are