Didn't see this up thread: I purchased gift cards last year. Was considering maybe changing my airline selection this year, but I booked a ticket on WN recently and used a $100 gift card from last year. The total price was $119ish, so I paid $19 with my Amex. I was surprised to see the $19 credited for this year. Not complaining, just was not expecting that charge to be treated as a creditable activity.