Here is a interesting, hypothetical situation. What will you do if there is a MLM scam going on and it is in early stage. It is assuring 10% monthly return in bitcoins (of course it has that referral bonus part as well but it is optional, you don't need referral as you are getting 10% on your investment.). B'cause of it's early stage, people are investing happily and getting returns monthly. In short equation of incoming source money > outgoing money. By looking at situation, let's say this scam/scheme will go on two more year. There are some people who rip benefits from these kind of scams/schemes as they invest very early and in large chunk.
Will you invest in such scheme well before it vanishes with bitcoins/money?
No and never , MLM are only scam . Here the MLM is only the thing where you can see the upper level people are making lots of money but lower are getting into hardwork only .
It is just a matter of thing that how did the people will generate money in the MLM business .
It is just like the Ponzi scheme of the site that gives the return of 109-200% a month

that is totally scam and the site run continuously until the investment became slow.
To be fair with MLM people. I can say that not all MLM business is clearly a scam because most of them are good investment because they have a good product and they offer good opportunity for us to earn a lot of money by just doing networking or recruiting other people to be included in your team and that is why MLM is like a short cut for other people to be rich or get a lot of money so for me it is not clearly a scam for all MLM business because there is still MLM business that are good and worth to try.