Just ran across this on their page. My date is too far out to request a proposal to, but it looks like there are lots of options including a discount code AND you can earn free tickets based on how many people actually use the discount code!
I'll TOTALLY be using this since about 75% of our guest list is from OOT. Love it!!!
http://www.alaskaair.com/as/www2/flights/groups/Wedding-Travel.asp