When I was an infrequent non elite traveller, I used to always wonder why I got stuck in some crappy seat in the back of the plane and what it would take to get an exit row seat ahead of time. When I was building my silver status, I figured out how to snag them via the checkin kiosk. The ability to pay $15 as a non-elite on a DTW-LAX flight, well, could actually make a positive impression on those passengers.