think about it this way. by giving you a free coupon, they reduce their own profitability. so maybe it is worth it for them to let it expire
That actually is a smart and intuitive way of looking at it
For me I think its just ballsy and more of an insult to offer $1 for $100, so no matter how many $1 I won't earn from the OP's generous offer, I'll still be ok
Thanks!