Hey my friends

this is my first thread and i have a question. i hope you can answer.
I got some Coins to my wallet.
i found this site http://www.metaverse.mozellosite.com/home
this is from another forum where a user made this for the people there.
first i was suspected, but now i got some coins to my wallet. i exchanged them to bitcoin and it worked also. i dont want to write the amount here, but its a lot for me.

my question now: how do they earn THEIR money when they give it to people?
i know it is mining with mobile phone but how is ist possible with low energy? 
i got it. im very happy but i want to know how they earn. i didnt gave them one cent...
thank you very much for your answer