Multi Level Marketing or MLM is totally fraud business system. I have seen many MLM business and i have lost my money in that business. Bitcoin is legal but MLM is illegal so Bitcoin isn't ideal for MLM.
I was really not well aware of this business. Till now I havent read about it even once but now as I have seen so many contribution of opinions about this one thing, definitely care is needed. One must not be so blindly trusting everything that comes on board. Most of them are scam and thus they decorate the name of bitcoin as well. Keep yourself updated with news.