This one is just a potential home run if you can get the 2x Seattle promo. Even without it, it is a nice deal. You can do this on weekdays or weekends at near the same price. If you play with airports around SEA ie up to a few hundred miles you can get EVEN MORE! Here are the numbers without the 2x promo:
Cost $975 in 1st class
12,056MQMs a 8CPM (again without promo)
Bookable on Delta.com
Coach trip DM yields is 22,100 Skymiles per CWSI.net
As you can see with the HUGE amount of MQMs and Skymiles this can be a very reasonable run. If you can get 2x for everthing, you are talking sub 4CPM in 1st class. Staggering and makes me wish I lived in SEA! – WOW!