How do cloud hashing companies profit? (leasing hashing power)
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.