Up there near the top of my list right now is multi-level marketing. Just a hair of a step below pyramid schemes and just this side of being illegal. Usually. Let’s start by getting on the same page – or better yet, Wikipedia’s page.
The main things to take away:
[Distributors] are awarded a commission based upon the volume of product sold through their own sales efforts as well as that of their downline organization.
and
Independent distributors develop their organizations by either building an active customer base, who buy direct from the company, or by recruiting a downline of independent distributors who also build a customer base, thereby expanding the overall organization