Well, that's true, but it is calculated a bit differently for bonuses.
For dice, our house edge is 1.88%.
Say you deposit 1 BTC, and you stand to unlock 3.01. The wagering requirement would be 1555.88.
So, to calculate the EV,
1555.88 * 0.0188 = 29.25
Right, so the expected value of the bonus is negative if you were to continue to wager your own funds to unlock the bonus, but the fact of the matter is that the deposit itself is zero-risk.
If you're not happy with the outcomes of the games, then you can just cancel the bonus and play with your regular deposit. From the site:
The fact that it is zero-risk, to me, guarantees that no matter what, unlocking the bonus is a chance with expected (though unlikely) positive results that you take in order to get 301% of your deposit. When I talk about Expected Value in the case of a risk-free bonus, I'm talking about the face value of the unlocked amount. If the bonus had some risk involved, then obviously at these numbers 50-80x would make it more likely, but if you're looking to get 3x of small wagers, then just play the games. We are offering a way to get 3 times the total deposited amount while not taking on any risk - I don't see how this is unfair.
We're not looking to get people to keep depositing their money in order to unlock an unlikely bonus - you can stop at any time, and we don't hide any of the bonus information from anyone.
And we certainly aren't keeping your deposited funds tangled with the bonus amount, that would be ludicrous. We're giving a risk free shot to deposit money, try your luck to get 3x the deposit without taking any risks (unless you choose to).
I fail to see how this is unfair to anyone. The fact that it is extremely unlikely, to most of our players, is irrelevant. They have a fair shot at doing it - just as they have a fair shot at unlocking the no-deposit bonus, and we're not going to force anyone to play through their actual deposited funds.
In the end, even a modest bonus of 2 with a 30x rollover would net you a .1 or so and the possibility of losing all your funds.
Take as much risk as you want - our bonuses give people a fair shot to win without exposing them to excessive risk. Our players happily take the bonus to test the system to check our provably fair system. Some win it big, and some don't, but that is the nature of games of chance.
This is just plainly not the case unless you wager your amount down to zero. Most players will withdraw their funds long before they get to this point. When the prospects are not good, withdrawal is the best option. We do not stop them from doing so if they don't meet the bonus requirements or choose to cancel their bonus.