For the airline , the management challenge is to identify those differences and price according to the demands. There are people who have to get on the airplane to go to somewhere emergency. They book the tickets in a really short time, if the airplane is almost full, the price will go up a lot; if the airplane is half full, he probably get a cheaper price for the ticket. Also the seat preference will be another demand for setting different prices. From my limit flight experiences, the seats with cheaper price usually are set in a limit choice. It means passengers who purchase the tickets only have few seats choices.
If I overheard the person in front of you in line getting a better room rate at a Hilton Hotel, I probably will comfort myself her/his room is not as good as mine. It happens that people could get a cheaper even free room or ticket if she/he has time to find out the hotel is full or empty. But I would not do that, it’s time consuming and it is usually for people not follow the schedule.
People who tend to get the better fare, they could wait until the last minute, and they will ask if there is any cheaper or free ticket go to the destination. And they also could book ahead from other people to get cheaper tickets with limited choice of