Interestingly the cheap FC fares on ex-SEA routes to compete with AS also allow for some good FCM offers for SEA-XXX-ZZZ routings. I'm flying SEA-MSP-MSN on Dec 9 and the difference between Main and First on the itinerary I booked was $280, but I got a FCM offer for $106 on the SEA-MSP leg. Good deal since the MSP-MSN leg is so short (and likely to get comp PM upgrade).