You may have never heard of multi-level marketing, or you may have seen it all over your social media feeds, or be part of the industry. It is controversial with passionate supporters and outspoken critics.
We hear some of the success stories, as well as women who say they have lost thousands of pounds.
Mumsnet tells us that its users are so worried about multi-level marketing that in the past couple of years there were between 20,000 and 30,000 posts about it on the site. MLM adverts are now banned from Mumsnet.
Produced by Natalie Truswell
Filmed and Edited by Andy Brownstone