MLM is really not an industry in the same way that steel, construction, computers or video are industries. Rather, it is a marketing concept which can be applied to almost any consumer product or service. MLM takes advantage of what has been termed multi-plex income. Certain businesses and professions offer the opportunity to earn tremendous linear incomes including the film industry and the legal and medical professions. But most linear income positions provide only limited opportunities for acquiring any great amount of wealth.
Residual income is another well known method of earning money.
It is the prime income source in the insurance industry where a salesperson earns income this year from policies sold in past years. Song writers, record artists, TV actors, and authors also earn residual incomes. Multi-plex income, however, takes advantage of the efforts of others to make money for you. It is similar to the way many major corporations earn their income. They rely on the efforts of a network of independent distributors.