Received via email tried it on 2 different accounts and it works on both so not targetted.
BTW, the hack is this actually gives you $5 credit so if you're at one of the few machines around offering $1 rentals at the moment (for eg Golden Grove SA) then you can rent 4 DVD's for absolutely free as long as 2 of them are 'family' (no my maths isn't out - you can only get 4 because you can't rent 5). If they still have cheap Tuesday it might work then too.
I've rented twice at Golden Grove with this code now and not paid a cent for rentals.
thanks, might head down to Golden Grove