as an example, I've rented from Alamo enough times, I know that if I show up early and use the kiosk, I have a high likelihood of seeing a different rate from my reservation. so if i do show up more than a few minutes early, eg 30+m, I relax and browse the internet. i'm old enuf that one doesn't have to swat me on the head until I get in line, assuming they are someone I want to "play" with...
i have a lot of admiration for Alamo because of their no deposit policy, eg beyond the actual estimated cost of the rental, so happy to abide by the terms of the reservation that I made...