MLM began in the US in 1959 when two business partners started a company with a unique business model. They believed sales representatives should be compensated for ongoing business generated by those they recruit. MLM involves multiple levels of sales representatives who market products to customers and recruit and train other representatives. Representatives earn commissions from their own sales as well as sales of those in their downline. There are different types of MLM compensation plans including unilevel, matrix, binary, and stairstep plans. Health products tend to be most commonly sold through MLM.