Multi-Level-Marketing (MLM) companies are big businesses around the world and they have rightfully attracted much criticism for questionable business practice. Many have called them illegal pyramid schemes, but today these companies continue to operate in most developed countries around the world and rake in billions of dollars in profit in any given year all with the blessing of local trade authorities. So, what are these businesses? Let's park personal opinions on how annoying it is to be roped into one of these MLM meetings for the moment and assess the fundamental economics behind this business model.