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, even if I knew beforehand that I will profit from it I think it is immoral to profit form the disgrace of others, so I will avoid dealing in any kind of dirty business like that since I like the idea of sleeping without any worries in my mind.