https://bit-x.com and hashnest are those that come to mind that are legitimate.
yeah, you are one of examples, that it can work, anyway generally "cloud mining" is for me:
1* non profitable
2* ponzi scam
Agreed. The only difference is the time it will be needed for you to loose you investment (in 99.9% cases). With ponzi you loose fast, and with legitimate cloud mining your death is slow and painful to watch.
Just think about it; you are no longer mining yourself, but are involving third party to do the mining, it's obvious to see that you are the last one in the food chain in that case, which comes with little or no reward at all.
My advice is; if you can't mine yourself, don't mine at all.
cheers