The most doubtful thing about this site is the rate at which it has paid. No site can earn at this rate and even if it does earn, then why should it offer such rate to the members...? After all they are here to earn and not for charity.
So at some point of time they will turn out to be scam. Initially they will pay and you will find some payment proofs too. But as soon as they have collected their targeted money, they will stop paying. So even the payment proof is not reliable thing for such sites.