[Butch Cassidy Slept Here]

I know what the next "chapter" in this story will be: NORTHWEST to YOU—‘Since you obtained that certificate in violation of the terms you're due nothing.’ Suprise, you're sc***ed!

As to the situation of the "OP:" What is to prevent an airline from falsely claiming a given certificate was stolen or is otherwise worthless? Doing this often enough can save a lot of money! The government isn't going to do anything about it. Yeah, right, send a complaint letter to the DOT--ha!

Most honest businesses are very up front about the fact that they don't offer "free lunches." For some reason the government allows airlines to offer frequent flier programs and other promotions the "perks" of which all too often are not honored. Part of the problem with these promotions is the seemingly endless rules. I'm sure one poster on here will have us all believe any given rule can be located--on a computer, or through a phone call to a "friendly" agent--in a matter of seconds! Believe that and I'll sell you a baby dinosaur!

This is another example of why US-based airlines should be regarded as no better than a dishonest used car dealer. Purchasing a fully refundable ticket is the only way one can have a significant measure of protection against rip-offs. Based on the posts on this board non-refundable tickets seem to provide no transportation as often as they DO provide transportation. A $99 non-refundable trans-continental ticket may be a good "gamble." But one should always remember, it's nothing more than a gamble. If you "lose," will you be sleeping on the airport floor??