How do cloud hashing companies profit? (leasing hashing power) I think I'm missing something. There are a bunch of cloud hashing companies that lease hashing power. Let's take cointellect for example. They have contracts from 10 days to 24 months. If I buy a 10 mH/s of hashing power from this company for 99 euros, they guarantee a minimum of 2.2 euro daily return which makes 180 euros in return for my initial investment of 99 euros in the 3 month contract. How is this profitable for both me and the company? What's the math behind this?
When you're calculating the profit from Bitcoin mining, you take into account the current bitcoin price, how much hashpower you have, and the current difficulty.

Difficulty rises over time. (Generally speaking.) Between Jan '12 and Jan '13, difficulty rose by a factor of 2.9x.

Between Jan '13 and Jan '14, difficulty rose by 407.2x.

Between Jan '14 and now, difficulty has risen by 33.3x.

Unless they're guaranteeing 2.2 euros per day over the course of the contract, in which case they're either morons or liars. (If you really could guarantee that kind of return, investors would be all over you.)

Of course, as David Schwartz notes, it could also be a scam. They could give you good returns, then vanish after lots of people invest.