Multi-level marketing has a well-known image problem, because there is not always a clear distinction between legitimate network marketing and illegal "pyramids" or [Ponzi scheme]?s. There are, nonetheless, many legitimate NM/MLM businesses operating around the world. See Companies for more info. Critics contend that some companies produce revenue primarily by attracting new participants, as opposed to selling products. Amway (the world's leading company in network marketing, with annual turnover exceeding USD $1 billion) in particular is often criticized for the fact that it generates considerable revenue from selling instructional and motivational materials to its participants. The company was indicted by the US Justice Department, but was acquitted.
See also: [MLM Watch].