It used to be that paying extra to pick your seat when booking wasn't as common. We showed up at the airport and got seats together. Simple.

So a few years ago I'm traveling with spouse, 5 yr old and lap baby. The option of paying extra came up when I did the booking, I looked at the seat map, saw that the entire front of the plane was already pre-booked and figured why would I pay extra for a crappy row at the back when I'd get a crappy row at the back by default? It never in a million years crossed my mind that they'd seat a 5 year old by himself. I pointed out my son to the gate agent. Sorry, nothing she could do. So I plunked him on the counter and said I hoped the flight attendant would have fun looking after him. Yeah, she quickly found us 3 seats together.

That said, I've never used that threat again. I now shell out the $120/vacation it takes to get the 4 of us pre-booked in 2 adjoining rows.

Aside #1: Kids get zero discount on tickets. So...why bother even asking for ages when booking flights if that information won't be used to make logical seating arrangements? Like the woman above who got upgraded, leaving two small children on the same itinerary behind in economy.