NW Golds and Plats receive a handful (8 or so) of AS upgrade certs each year--this year I think it was upon request. They provide immediate upgrade at time of purchase on full fare tickets and may be used along with the hoi polloi upon checkin day of travel for other fares. Upgrade success isn't particularly high for me, as I'm most frequently on busy OAK-SEA or OAK-ANC flights, but it beats a poke in the eye with a sharp stick.