Back in the day, I've setup the back-end for hundreds or even thousands of smallish MLM companies. Trust me, vast majority are all bullshit.
The multi-level, but unlimited width of levels isn't generally known as MLM. It's known as a "multi-tiered direct / network marketing" program. MLMs are generally pyramid shaped (ie. forced matrix), so say 3x5 matrix. First 3 people you recruit are on your 1st level, then the next guy is bumped down to your 2nd level under one of your first 3 recruits.
Then of course, there's recycling, reversing, split level matrixes, and tons of other really retarded shit. Point is, these companies entice new members with their comp plans, not their products. "All you need is 3 recruits, and shortly after will have an organization of 850,000 people, all kicking up a commission to you!" type of bullshit. Or the "signup under me, and the spillover from all my recruits will get credited to you!" line.
That, and the entire MLM industry in general has its head in the clouds. There's nothing tangible there. It's all just hype, hype, hype... nobody ever steps back and bothers to setup a real business. It's just a bunch of lemmings running around trying to sell each other intangible dreams.
Not saying you can't make good coin off MLM if you're a good bullshitter and manage to put yourself at "guru" status so you can speak at conferences, and sell courses full of pure bullshit for $1997, but just saying... it's not real.
Trust me, I was setting up MLM back-ends for over 5 years, day-in, day-out.
