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Comment by beambot | Hacker News Reader

All it takes is a loss factor of a few percent, and the entire model breaks down.

This is the same reason that long-range RFID (UHF RFID) never worked for cashierless checkout too. You couldn't ensure 100% coverage. Some tags just couldn't be read -- either due to adversarial tactics (eg. shielding with your body) or material properties (eg. metal) -- and the engineering countermeasures to overcome these challenges made the tags too expensive for low-margin goods.

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Amazon can realistically do something run-of-the-mill shops cannot: choose its customers. In any case, this is bleeding-edge territory. The point of such experiments is to measure and modify. The margins are too close for armchair philosophising.

I have seen supermarket chains do away with automated checkout (Jewel which parent company is Albertsons) systems because they increased loss factors.

Here in Australia our two major chains just convinced the police to station publicly-funded officers in the checkout area: http://www.news.com.au/lifestyle/home/crackdown-of-self-serv...

Cut staff numbers without having to pay for increased security! That's just good business sense.

I'm the US we have the same thing... It's just informal, and being done by Walmart:

https://www.bloomberg.com/features/2016-walmart-crime/

> without having to pay for increased security!

They don't pay for the police?

No, the police are paid for via taxes.

Oh. I assumed Albertson's dropped these because they were slow and inefficient, not because of loss/shoplifting. The stories I can find about it suggest the same.

Jewel/Albertsons also tried portable hand-scanners to speed up the checkout process. That quickly was pulled as well.

I guess it depends on how you set them up. In the UK you'll find self-checkout scanners in nearly every supermarket that contain scales. Stealing with those isn't easier than just stealing in the first way. You can't just "forget" to scan an item.

Scanning while you shop, however, doesn't really seem to work. Tesco tried that and basically stopped it again. You either need to check really often (high staff costs) or will have losses.

> Scanning while you shop, however, doesn't really seem to work.

Carrefour does that in France, and it works like a charm (I've used that for years when I used to live there). They run semi-random manual inspection of your grocery bag at checkout (happened like once every 1-2 months).

RFID is expensive. Even buying the cheapest transponders in bulk, you're still looking at $0.01-$0.05 per label - that's enough to kill the concept entirely for high-volume, low-value goods such as supermarket/grocery store goods where the profit-margins are thin enough as it is, if not loss-making.

How much per item do you pay for cashier staff though. Might be the same as the tag cost. Also in regards to RAIN RFID tags vs dumb print tags yep you are talking about a 5 cent increase. But you also lift inventory accuracy from ~70% to 99.9%.

You still need some staff, sometimes items are damaged, the item doesn't scan, the payment won't go through, the customer changed their mind etc etc. You can't get rid of all staff.

You can just replace them with self-checkout. You still need some cashiers (as you would with RFID) and don't have the cost of extra tags.

A cashier can process tens of thousands of items per hour, at a wage of under $15 per hour. This means that the cost of a cashier can be around 0.1¢ per item sold for a busy store

Generously assuming a cashier can check one item a second for an hour, he can check only 3600 items. "Tens of thousands" seems off by at least an order of magnitude.

I was thinking of some costco cashiers I've seen, and they do far more than one item per second. That said, when you consider the downtime of processing the transaction, your estimate is probably not too far off. It makes the low end cost of transponders comparable, though just.

This seems easy to estimate. At my local large suburban supermarket doing weekly shopping for a hungry family I have a receipt with the last line listing "53 items". So at 5 cents per tag, that's $2.65 of tags ending up in the landfill per week. The cashier takes less than 5 minutes for the entire transaction including scanning and payment and small talk, so (5/60)*7.25 = about 60 cents. Now cashiers are not 100% busy and get breaks so I would round the ratio down to RFID is currently about 3 times more expensive than human.

Of course a cashier can supervise up to 16 self checkouts in a low crime demographic area, so add in a new factor of 16.

For people who don't care about cost and scoff at $2.65 per visit, for a mere $9.95 they deliver...

Tags used to be 60 cents. Now 5 cents. If they got used for masses of things e.g. groceries, they'd go down to a negligible cost. Folks like WalMart can actually drive this themselves.

Walmart already uses RFID in the backroom and for palettized loads, but not for stock that customers handle.

In my own work with RFID, the main problem we have is (after disregarding the cost of the transponders) is getting someone to put a transponder sticker on every single widget - stores already stopped using those "pricing guns" when they adopted UPCs/EANs, they don't want to regress backwards.

The solution is universal adoption of the EPC RFID system, but that requires all suppliers and logistics infrastructure to also adopt it. It's happening... just very slowly.

If they got really cheap, you could imagine 'spraying them on' a pallet and then wanding each item in. Combined with a simultaneous read of the RFID tags that 'stuck', and presto. Just brainstorming.

If they're using serialized EPCs (which track a unique item, not just SKUs) then this won't work because need to ensure each physical item is uniquely tagged, and that two tags with different serial numbers aren't on the same item (though duplicate tags with the same serial are fine) and that no two items have tags with the same serial.

If they're using non-serialized EPCs (so just logging SKU) then they need to ensure exactly 1 tag is on each item - no more and no less - otherwise inventory counts will be inaccurate.

Unique tag serial numbers would work fine. No duplicates (don't even understand how that would happen). More than one tag not a problem (enter one or all; whatever, as long as scanning later identifies the one item).

i imagine any such store has a ridiculous amount of surveillance with probably a membership model like costco with scanning so they know who you are when you enter the store. more than do-able these days.

i honestly don't want amazon to continue to get bigger it's already big enough as far as i am concerned, but that's not how big business works. consolidation is the way and the government does little to discourage it and allow smaller players and more diversity.

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