This is not financially sustainable for them assuming they're a legit business, there's no way in hell they're able to make so much on such tiny amounts of power, and the minimum deposit amount is so much more than what you'd earn from their 15kh/s and that wouldn't pay out as they basically delete your account if you dont send them money within x time. All you're doing is paying for the people who have made big investments to be able to withdraw coins, eventually less new users will come to keep that pot funded and it will crash, avoid this site!