This worked fine. I made a roundtrip reservation over the phone in Canadian currency for my daughter and me. The total price was $130 Canadian. The clerk told us to bring our coupons along.

We printed out the coupons, gave them to the bus driver, and he said he would give them to the office. They refunded $26 to my AMEX card, so they did exactly what they said they would.

For comparison's sake, Greyhound costs $43 US roundtrip per person to get to downtown Seattle. You then either have to take an airport shuttle (like the Grayline that leaves near the Westin and which costs something like $10, although I don't recall the exact amount) or a cab (about $30 US). If there are two passengers on Greyhound, you can get the second ticket for 50% off with the Companion Fare discount. At any rate, I think the convenience of QuickCoach is well worth it for a dropoff right at the airport.