It's a common question made by who is new in this world, and the answer is always the same, it's a scam.
If you see about the genesis mining and hashflare it looks like the legit cloudmining site but it will never give back your ROI and it's also including on the scam site. 
I think both have been around long enough to survive. And isn't genesis mining part of the Winklevoss exchange genesis? They are the one's creating the bitcoin ETF. So they will only run if their ETF fails to get approved and then their exchange of bitcoins loses enough money and goes under.
If we talk about hashflare.io - is listed on http://www.badbitcoin.org - some people are sure that they are legit, but I personally doubt in that.
I also doubt if Genesis-Mining have anything to do with Winklevoss brothers - any source?
Genesis-Mining many times show that they really have mining farm, anyway from long time contracts with them are not profitable.