Email is to keep track of all your bets that you have sent
The game doesn't seem to be provably fair, and you haven't mentioned how the numbers are generated in each round.
Plus, the "News" and "FAQ" page are just empty. It would be way better for you to open business after everything is ready.
here : https://www.random.org/
Not sure that if you use random.org for the roll number since there is no provably fair here means there is no guarantee that your game is fair. You can easily choose the bet with the lower wagered there so that you dont need to pay out alot more and keep the profit for yourself. No offense
Ah.. I don't know how to verify this game with random.org either. I'll stay away..
Btw, my bet : Small , result : big
Edit :
Their system automaticaly forwards the fund to different address even though the tx has 0 confirmation, I have no idea about this, but looks suspicious.
There is no way to verify this game, random.org may be their way of choosing the number but it is not a guarantee that they are fair.
i.e
Small has 0.3 BTC bet
Big has 0.6 BTC bet
The site claim to use random.org. Since there is no way to verify anything, they can roll whatever number they want . The site probably will let small win since the bet in "small pool" is much less compare to the "big pool"
so 0.3 BTC x 2 = 0.6 BTC assuming they do 2x payout and pay for the miners fee
They are still in profit for another 0.3 BTC from the "big pool" bet