>What you want to compare is how long it takes at a staffed queue vs an unstaffed one once you get to the front of the line (for the same purchase). Maybe if y

>What you want to compare is how long it takes at a staffed queue vs an unstaffed one once you get to the front of the line (for the same purchase). Maybe if you're selling a checkout system. Personally I care how fast I can go from "got things" to "left building". (or maybe more accurately: left home -> returned home, but that has a lot more variables)