Smart Coupons

Would be great to be able to validate coupon usage depending on whether the coupon has been used with a particular credit card/PayPal account/etc. already. Quite a few other online retailers invalidate coupons if the coupon has already been used with the same credit card, or a combination of factors (e.g., email + address + credit card). Option to validate someone’s first order by a combination of several items would be incredibly helpful to avoid people continuously creating new accounts with ‘fake’ email addresses.