It sometimes (once every few months) goes down when AS decides to make a huge "improvement" to alaskaair.com - since the service relies on AS's web site, if their site is down, or makes significant changes to their design, I have to update it on my side as well.

In its history, it has never been down for more than 2-3 days though, so if it's ever down just shoot me an email and wait a day or so and check back