Originally Posted by
SchmutzigMSP
Hardly anything from NW is transferable, so you should really never buy any coupons, vouchers, etc. from eBay unless you're prepared to deal with the consequences (NW can and will retroactively debt your account, close it, etc. as is their right).
There are a lot of unscrupulous people on eBay. As always, caveat emptor.
The coupones they offer for missed or late flights. Ask for your FF#, so I guess you could sell them, versus redeem them yourself.