I did _not_ realize that Wal-Mart was also rolling out a version of this called Scan and Go.
The win here is correctly identified by the reviewer: a dramatic reduction in wait time in line.
"Getting the hang of Scan & Go can take a few minutes, and it's not faster than simply self-scanning two or three items. Beyond that, Scan & Go works surprisingly well. Sure, it takes more effort than simply letting a checkout person do everything for you, but it can make shopping seem faster because the checkout phase is greatly speeded up."
The win for WalMart is clear: they don't have to buy a bunch of scanners, because customers use their own phones; they just have to supply an app, and they've chosen to do so in their existing app and requiring an account, thus accomplishing multiple goals: target ads at the right eyeballs, establish a relationship, reduce the bar to future online shopping by the in-store customer, etc.
You might think, yeah, but WalMart's customers and smartphones? Well, it is apparently not a problem. Which says a whole lot about smart phone penetration in the US market.
I'm working on a prediction about the future of queuing: I think it's going to go away, sort of. With high-touch retail (Nordstrom's, Apple stores), when you get a sales critter's attention, they make sure they get money from you before you have a chance to change your mind by following you around with the point of sale system (an iPad in both cases). With guaranteed repeat customers (grocery stores), you teach the customer how to do the checkout work and make sure it doesn't happen in a line context, because waiting for an amateur to scan all their stuff is excruciatingly painful. Last November, we experienced an early phase of the hotel-checkin-while-sitting-on-a-couch at BLT -- things were a little screwed up so we had to switch to the regular desk, but at least we weren't stuck in a line at the main desk at Contemporary, which can be very painful.
RHI Disney will be replacing FastPass with some sort of reservation system.
I think queuing is going away.