Critics accuse multilevel marketers of using slick pitches to persuade the unwary to buy goods in bulk, promising them that they'll make money by selling those products to others. In this way, the companies are paid upfront, and the rank and file bear a good deal of the financial risk.
Bill Ackman, the wealthy hedge-fund manager who reportedly bet $1 billion that Herbalife's stock price would fall, has accused the company of fraud, most recently in a presentation to investors last month. The company sells powdered protein shakes and supplements in what Ackman calls a pyramid scheme. Wall Street has heatedly debated his claims.
Herbalife revealed in March that it is under investigation by the Federal Trade Commission. The company has stated that it complies with the law and that it will cooperate fully with the investigation.
(See Washington Post blogs for more info)