I do not like to invest again in mining sites because i have a bad experience before that i got scammed and i do not like to happen to me again that is why for boosting my income in bitcoin i choose to invest in trading it is very convenient and easy to earn bitcoin.
Yeah it is proven, mining sites are ponzis! So stay away from it and even how legit it is, in the end you will never get your ROI before it declares its bankruptcy. Its proven and I myself too have the first hand experience on how they shutdown while declaring bankruptcy though the legit one offers you their machine but it is only for those who have enough hashes to availl them but for those with little hashes, is good bye investment.