The way I see it, if a cloud mining service can make more money mining then what they're charging, then they'd just mine. Having me pay them to mine for me seems like I'm losing out.
If they can sell their GH for BTC and buy more GH for those BTC they might make more money than if they just mine them self.
Please provide an example of how that might work. I think you will discover that it only works if the customer loses money.
If it cost them .01 BTC to make/buy 10 GH/s worth of mining equipment but can sell that equipment on cex.io for .07 BTC then they just made .06 BTC, they then use that .07 BTC to build/buy 70 GH/s and sell that for .49 BTC, and so on and so forth. The only difference is that the amounts are much greater (I am not sure about the profit margins though).
Suppose they can use the equipment to mine 0.08 BTC instead. Then why sell it 0.07 BTC? They make less money. And if they sell it for 0.07 BTC because it can only mine 0.06 BTC, then the customer loses.
Example: They buy 1GH of mining power for 1BTC.
Instead of waiting for the 1GH to generate 1BTC they sell it for 1.2BTC.
Then they use that 1.2BTC to buy another 1.2GH of mining power.
They sell that 1.2GH for 1.5BTC.
That 1.5BTC they buy another 1.5GH.
Now they got 0.5BTC and 1.5GH of mining power. They sell that 1.5GH, buy more GH and it goes on. Hope you understand me.