I assume this is a targeted offer (I received it via e-mail).
Receive a $50 flight discount after you spend $1,250 or more with your Alaska Airlines Visa Signature Credit Card at qualifying Book, Toy, Electronics, Sporting Goods, and Department Stores from the day you activate through December 31, 2014.
It seems like a pretty good selection of stores to make purchases at, and really, $1,250 isn’t a whole lot (roughly 4% if math serves me). The terms and conditions specifically state:
You will receive a $50 flight discount code on future travel if from the date you activate this offer through December 31, 2014, you make purchases of $1,250 or more at merchants which are assigned one of the following specified merchant category codes (“MCC”): Department Stores (5311), Electronics Stores (5732), Computer Software Stores (5734), Hobby, Toy and Game Shops (5945), Book Stores (5942), Sporting Goods Stores (5941) and Sports Apparel, Riding Apparel Stores (5655), each an “eligible purchase” for this offer. Please note that this list does not include MCC(s) commonly assigned to large discount retailers that are often referred to as “big box” stores or “superstores”.
So it probably doesn’t hurt to double check the MCC of particular stores if you plan to try to MS or resell your way to that $1,250.
Here’s a screenshot of the offer: