It's definitely not confined to Passport members;  it's open to everyone.    I'd assume that it's a once-only thing, per individual.  I've had a new e-mail from CP elaborating on the offer and displaying the coupon name in green-on-black, rather than the beige-on-off-white of the original (I don't fault CP's generosity, but I'd never have been able to read that coupon, as originally displayed, if Fejj hadn't deciphered it).