Another day, another dollar . . . of ancillary revenue that US Airways is hoping to get out of you. While you’re likely to hear the usual chorus of “boo’s” from the peanut gallery, this isn’t really a bad move for the airline or for passengers.

Here’s the deal. Right now, US Airways blocks off exit rows as well as windows and aisles at the front of the plane for advance booking by elite customers only. Actually, most airlines do this. So what they’re going to do now is allow non-elites to pay to reserve the seats up front (but not the exit rows) at the time of check-in if they’d like. Pretty simple concept.

Here’s where it gets a little tricky. Right now, those elite seats open for anyone to book at 1201a on the day of departure. So, if you check-in online before midnight, this is just going to be an added bonus for you that you can pay to reserve the seats. If you check-in on the actual day of your departure, well, then you’re going to have to pay for what was once free.

How much? According to US Airways, it’s “per segment, lowest will be $5 and at least $30 on the high end, subject to change.” So would you ever pay for this? It’s unlikely that I would. I mean, if I’m traveling with a family and we can’t get seat assignments together, this will save a lot of the hassle of shifting around at the airport, but I don’t have kids, so this isn’t a big issue for me.

But that hardly makes it a bad idea. It’s all about paying extra for added value these days. If people think this is worthwhile, then they’ll pay for it. If not, well, then they won’t. My guess is that US Airways isn’t expecting a ton of revenue out of this, but assuming there was minimal tech work involved, even a handful of takers will make it a profitable move.