"IIRC the checkout scanners enable the execs at these companies to watch their sales in real time.", can you provide any further information or links on this?
Shocking if true, and my quick google searching was fruitless.
At one time, I was the CIO for a nation-wide retail chain. All of our systems were real-time and we had the ability to see sales as they happened.
A lot of companies use local servers in store locations that dial home and upload data nightly. In the brick retail environment, that's pretty close to real-time.
When I worked for BestBuy the store had a mainframe. I thought to myself ,"what the hell do they need a mainframe for to run a store?" A region or a district I could understand, but most of the tasks for running a store could be done from a decent Windows box. I figured they bought a lot of them for cheap and needed for them to do something so printing SKUs twice a week was what they were good for.
When I got to university the guy that ran the IT department for Walmart gave a presentation on how they got real-time data on each store.
Any book on Walmart will talk about their IT systems. Their main operations room looks like NASA's mission control. I recall that Walmart can redirect trucks on the road via satellite to different stores whenever demand suddenly fluctuates.
As crad suggests in his reply, never, ever make the mistake of thinking grocery-store chains are managed by knuckle-dragging morons. Grocery retailing is a hell of an interesting business.
A grocery store is like a miniature, specialized Disneyland. Rule #1: everything you see, from shelf height to lighting to back-end IT, is intentional. Rule #2: in the event you see something that looks arbitrary or unimportant, see rule #1.
I don't know about the US (I suspect it will be the same) - but the chains in the UK compete with each other like a bunch of hyperintelligent velociraptors.
Quite good for customers though - in the (rather affluent) area where I live we have a Sainsburys, Waitrose and M&S food store and they are clearly locked in polite but vicious competition.
When you think about the tiny margins grocery stores survive on (1% is the commonly quoted stat), it's easy to see that they're forced to be well run. Make many mistakes and they're out of business.
Never make the mistake of thinking this is equally true of all chains. Some chains, such as Giant Eagle, are known for their data mining. Others just follow the leader.
Shocking if true, and my quick google searching was fruitless.