Cloud mining sites are huge companies that accepts investments from you in their operations to invest in Mining rigs to mine Bitcoin/altcoins. Genesis mining is so far the only one that is still paying and seems legit(Don't know ultimately though). I had invested about $40 in there which meant that i was to receive about $0.22 every day for the rest of my life. Now that can be a tempting thing to further invest more to increase the daily payment. The fact that genesis mining paid me consistently without fail convinced me to invest in hashocean, another cloud mining site similar to genesis mining that promised high pay.
I did invest about $800 total. On June 26th 2016, hashocean closed down their business and basically run away with millions of dollars from over 700,000 people.
This is to point out that most cloud mining sites are to be looked at carefully. I've learnt a lot of lessons, to be very careful and very weary of sites like that. So far Genesis mining is the only one that has kept to their word, but even with that, it could be so be careful out there. If you've fallen victim or you do(which you should try not to get involved), keep your head up, learn from your mistakes/risks and move on. Don't give up in crypto, Don't lose hope.
Be safe and careful out there everyone and be weary of sites like that. Take care and love you all :)
UPDATE
Here's my story and very unfortunate experience with hashocean with all the details: https://steemit.com/introduceyourself/@kakradetome/6ovhbs-i-lost-usd800-on-hashocean-cloud-mining-it-was-very-unfortunate-but-a-bit-of-a-blessing