Haven't seen anyone talking about this 'offer'.
If you are ballsy or stupid enough to put your social security number into a random website, wargaming will give you a Premium tank, crew, garage slot, and a premium style. Don't forget, another 10% off coupon that can't be used for anything you actually might want (actually, the coupon claims to work on anything except gold). However, apparently, you get a new coupon every day if you actually use it.
If you already have the tank in your garage (they do tell you this) you don't get the tank or any gold compensation.
What they don't tell you is you also won't get a garage slot or 100% crew (not that I need another one).
As usual, they never actually flesh out the details in anything they put on the internet.