..... delay usually happens for a big withdrawals and its good that Rollbit really follow the standards.
What standard? He was able to withdraw a larger amount of money within a shorter period of time if you look at his original post so I don't think there is really an industry standard for this.
....
Now gambler doesn't afraid about how much money they win, in the end Rollbit will pay them.
Long delays will always make anyone with huge withdrawals fearful.
Maybe if they are need time to send, it will better to give an ETA notification for users.
That would be tough since they are relying on another person or party to confirm if the bet is legit. It would be faster if it was their own employee.