Remember Dean's running higher-edge games now - roulette and lottery - and bankrolling them himself. Maybe he's making enough from those that he thinks he can afford to pay 30% referrals. The problem is that there's no apparently limit on the 30% referral, and since it appears to be +EV, it will attract a lot of action.
Wow, it seems this will attract all the luckyb.it crowd as well. Just create a referral for yourself(which obviously, can easily be faked), and win a lot of money. If you lose you still get a lot of it back.
But if you lose a lot, then maybe, Dean will reconsider if he wants to pay you the 30% or not. or maybe, he will just gamble against the investors to pay that amount off.