I looked into a couple of MLMs when I was a much younger man, and there were some things I noticed. First, to be successful, the MLM replaces your family, your friends, your church, and becomes THE #1 focus of your life. Every new acquaintance becomes a possible recruit.
The people in the lower levels of the MLM seldom, if ever, see any real money. It's the people in the 1st, 2nd, or 3rd levels who are getting rich. And those people in the lower levels have to buy large amounts of product themselves, to the point of sometimes losing money.
Thankfully, I never joined one of these things, and when I hear the term MLM I walk away quickly!