I agree the Coupon Code field is a taunt, but what if someone has a coupon code and has lost the url for the coupon-specific form, or just ended up at the main

I agree the Coupon Code field is a taunt, but what if someone has a coupon code and has lost the url for the coupon-specific form, or just ended up at the main form anyway? That could be especially frustrating - to have the coupon and not see any way of entering it. Perhaps another solution is to have a checkbox "I have a coupon" instead (and ask for the code on the next step) or a link. That's less of an incentive, but still keeps the option for coupon holders on the main form.