Well, if you really know about how mining works you would know that selling lifetime contracts is the real scam. A legit company wouldn't do that. So that's why I am happy that Genesis an Hashflare got rid of lifetime contracts fast enough.

"Lifetime" makes you believe that you pay once and mine for the rest of your life. Very wrong! Lifetime means you will mine as long as your mining result is higher than your costs. And then the contract terminates. The problem: Lifetime contracts are usually more expensive than 1-year contracts. Unfortunately you have no idea how long the contract will last. So ROI and the amount of return is very hard to calculate. With a 1-year contract it's still not easy (due to difficulty change) but you get at least a rough number when you reach your ROI and how much you can expect in relation to your investment.

So for me I never would mine with somebody offering lifetime contracts!