I posted on that other thread and I do fly US Air and I have never heard of buying a
seat for the dog, a ticket yes, now I think FAA rules state that the dog, with seat or pet type ticket, must fly in the carrier, under the seat in front of you, that's why you can't sit in just any seat on the plane, ie: the exit row, the front bulk head as an example, only so many "pets" on the plane at a time, you know the drill. With that said, the stew on your flight really is the person who makes or breaks those rules. Like it or not, it's their plane, you are their problem. And as pi$$y as they can sometimes be, mostly, they are way too busy, too many people on board these days. Sorry, that really doesn't help or explain the why or why not, I think it's just one of the "IT IS" things. I always just make Sprocket's ticket part of my planning, and I'm always looking for the cheapest way to fly, BTW I hate to fly, it's a "cattle call" but sometimes you just have no choice. Oh an other thought, sorry, I thought for every "seat" type ticket sold they had to have a piece of picture ID there is an accounting through the gate. Maybe someone knows better than I do or it only looks that way.
I also would really like to know cause it's expensive, but
I don't trust the "system", what one person tells you, on the phone, is not necessarily what you will get at the counter, even it you have bought the ticket already. BUT in the bag, under the seat, take off and landing, the rest of the time in my lap, USAir was great, Sprocket did well, and the stews were the best. Maybe small airlines would be more flexable. Sorry to not be of more help.