Voucher
By saying "go to the counter", but making sure that the counter is closed when my flight arrives, or that the counter in another city is outsourced to ground handlers who have never seen 1 of these before, the value of the gesture is diminished to less than zero.
I will give it to my neighbour to put in the internal mail (hence saving the stamp) and wait 90 days for their "gracious" offer to be paid up.