http://www.alaskaair.com/www2/Promo/...asp?pid=NW0302

2-4-6-8, who do we appreciate? You!

Earn Up To 20,000 Bonus Miles When You Fly on Northwest Airlines® and Alaska Airlines / Horizon Air

2 segments on Alaska Airlines / Horizon Air and 2 segments on Northwest - 2,000 miles
4 segments on Alaska Airlines / Horizon Air and 4 segments on Northwest - 4,000 miles
6 segments on Alaska Airlines / Horizon Air and 6 segments on Northwest - 6,000 miles
8 segments on Alaska Airlines / Horizon Air and 8 segments on Northwest - 8,000 miles
= 20,000 miles total

Since a single round-trip ticket on each airline includes at least two segments, that free ticket could be yours before the last game is played! Not to mention, the regular mileage you earn on your flights will help you achieve - or maintain - your elite tier status in Mileage Plan.

NOT VAILD ON NW FLIGHTS 1-12, 14-99
(these are the international nonstops)