Jack Sinclair:

Companies that pay you to sell products and recruit others to sell are called network marketing or multi-level marketing companies. In network marketing, the effort is in building a group of others that also sell the product (called a downline), and then receiving residual income based on the sales of everyone in your downline. It is one of the more popular ways to earn residual income, but also one of the riskiest methods, due to problems like poor business plans, non-compliance, and management corruption.