The local Walmart expanded self-checkout and it works surprisingly well (the bag scale seems to be very loosely calibrated or off). I wonder if they're doing things differently depending on how much product walks out the door.

Just in the past month or two, in my (low-crime suburban) area, Walmart appears to have closed the two large self-checkout areas entirely and replaced them with a (relative to before) army of cashiers. I have always found their machines to be very hassle-free, but the shockingly-adequate level of cashier staffing made my last visit surprisingly quick and convenient. I could live with this.