The Direct Selling Association (DSA), a lobbying group for the MLM industry, reported that in 1990 only 25% of DSA members used the MLM business model. By 1999, this had grown to 77.3%.[26] By 2009, 94.2% of DSA members were using MLM, accounting for 99.6% of sellers, and 97.1% of sales.[27] Companies such as Avon, Electrolux, Tupperware,[28] and Kirby were all originally single-level marketing companies, using that traditional and uncontroversial direct selling business model (distinct from MLM) to sell their goods. However, they later introduced multi-level compensation plans, becoming MLMs.[23] The DSA has approximately 200 members[29] while it is estimated there are over 1,000 firms using multi-level marketing in the United States alone.[30]

The legal distinction between MLMs and traditional pyramid schemes has been characterized by many authorities as a legal fiction. Jurisdictions that retain a legal distinction between MLM pyramid businesses versus illegal pyramid schemes retain said distinction on two key distinguishing features: 1) that MLMs always encompass the sale of actual products/services, while traditional illegal pyramid schemes ordinarily do not (though sometimes they do), and 2) that climbing an MLM pyramid is overwhelmingly statistically improbable (especially to its highest participant levels) but not theoretically impossible, whereas climbing a traditional illegal pyramid scheme is both statistically and theoretically impossible.[citation needed]