I too are starting a cloud mining services... but unlike Genesis Mining, should any of my customer decide to pull out i would send them back the GPU they have invested on. Instead of buying HASH its investing in the amount of GPU with the Tariff of USD 0.08. But of course i get to keep 20% of the findings each month but with a twist. The mining goes to the customer's account then paid to me at the end of each month.
I am also thinking of starting a coin that is backed by these cards... the more people invest in the coins then the more cards and farm i would start and appreciation of the coin value when more ALT COin are farmed... it would mostly be ICO then lead to Proof of Stake, only problem is that it wouldnt be so decentralize anymore.
Sorry if this is in the wrong place admin ...
your way may work and i think your one the first one to do that beyond bitmian or bitmian used to do that or may still you actually get the gear if you want it but only after they start taking that contact off line but you offering it with no waiting if they pull out and want the gear, hope it works .
to me that's not really cloud mining like they do now, it's more a hosting service .