It has worked OK for me (Club Rouge). The amounts are predetermined of course, and spinning the wheel just shows you what it is that day. It can't take your account number into consideration because when you click through to the claim form it does not pre-fill the account number as other promos do. The wheel also shows the same result if accessed through the website instead of the lobby. Whilst this means anyone can spin the Club Rouge wheel to see what we get, the claim will fail once you fill in the account number.
I didn't think there would be any targeting other than between Club Rouge and non Club Rouge players. If geo targetting was used, it would produce odd errors in some cases because it can misallocate players who are close to borders as they may get given an IP address by their ISP that is tagged to the nearby country/state rather than their own. It would also mean that players using mobile devices would get different levels of bonus depending on which "hot-spot" they used. It would, of course, be open to abuse if certain countries were favoured by the big prizes.
One drawback of this promo is that you have to spin the wheel to see how much that day's minimum deposit is. A better idea would be to have a fixed deposit amount (or at least a fixed maximum) which then buys you a spin on the wheel inside the client. This would mean that deposits would be made on non-bonus days simply in order to find out if there was anything. The prizes could then be tailored to each specific account such that they were bigger for players who had made plenty of deposits outside promotional offers, and lower for those that only deposited when the bigger bonuses were offered. The design would allow up to 60% of days to be "no bonus" without calling the fairness of the wheel into doubt.
Initially it was called "Red or Black", but mysteriously became "Spin the Wheel" at some point - so who leant on
32Red over trademark issues? (The TV series "Red or Black" perhaps

).