The barrier is the mental cost of context switching. You find your item, scan it, and then have to go check your list to remember which item it was you needed. You also need to find the barcode while the regular checkout has both a bottom and side scanner, so you just pass the item over and most of the time it will catch the item.
I don’t use them because I just assume it’s going to be a personal information harvest fest, and it won’t work as advertised anyway. Like most other software-driven things these days.
It's basically the same technology that's used at the register. You pick up a barcode scanner, you scan your items, and the scanner produces a hash of your items that can be scanned at checkout to reproduce the list. Super simple technology.
The store could gather how much time it took you to scan between items and in which order, but you can pay with cash if you're worried about personal privacy.
Personal information is a fair point, though that goes for any loyalty program (which I presume you also don't use), but what do you mean by "won't work as advertised"? The function that's advertised is that you can scan items as you walk through the store and once you get to the checkout the only thing you do is pay, which is exactly the function that's provided.
Unless you pay with cash at the grocery store, they are already harvesting it. I’m surprised they are not selling it to the health insurance companies to monitor your habits.
Believe it or not; that type of behavior was not always deemed acceptable, and has largely been an artifact of the tech boom making mass information processing and transfer easy to do. Besides which, if they did, it isn't that big a leap to realize a second coming of HIPAA would soon follow, as people are quite understandably very sensitive to the nature of what inputs are allowed in terms of actuarial processes. Remember, your insurance provider having more information is almost always strictly worse for you in the long run. They are out to maximize float. Even of they can't try to dissuade individuals to drop out of the risk pool anymore through individual medical underwriting, they just bumped the actual filtering up a level of abstraction.
At least some of the Ahold Delhaize subsidiaries (Food Lion, Hannaford, Giant, Stop&Shop) have handheld scanner kiosks you can checkout when you enter. I know Giant and Stop&Shop also offer a smartphone app that operates the same way as the kiosk units using your smartphone camera to scan.
I've seen the kiosk system at Kroger in the midwest.
Sam's Club offers a mobile app scanner.
Perhaps it's just the places I frequent, but I've gotten to the point where I take them for granted. Keep an eye out for a kiosk that seems to be a kind of fnord. Check if your nearby groceries have a smartphone app that offers scanning via your phone if you're comfortable with that. The ones I've used worked fine, but I tend not to use the phone apps because I have a chronically low smartphone battery and storage space.
The Kroger stores I go to always have that, but they always seem to shut it down around 6pm, and I get off work at 7pm, so it's kinda useless to me haha.
They introduced these at the grocery store my wife and I frequent. We used them just once. As long as the lines aren't long, it seems just as quick to have the 2 checkout people (1 cashier, 1 bagger) do the work in a batch at the end, as opposed to fiddling around with bagging as you go.
That's generally not that person's only job in the market though. These same people generally have mild janitorial duties, keeping the front-end stocked with supplies, and act as general go-fers (helping people find things, putting things back on shelves, price checks, etc.) This sort of role can make things way more efficient.
In my area of the US most stores don’t have baggers. But in those that do I’ve found they are often either very young (likely a first paid job) or have some form of mild mental disability. It kinda seems like stores having baggers is kind of a jobs program/public benefit, making the inefficiency less of a problem.
In Sweden, this has been a thing in most larger grocery stores for more than 10 years, e.g. https://translate.google.com/translate?sl=auto&tl=en&u=https...