Most people assume the price on the shelf is the price for everyone. You reach for the same tin of beans as the person next to you, and you both pay what the label says. That assumption is quietly going out of date.
Two things had to line up first. Shops had to be able to change a price instantly, and they had to know something about the person about to pay it. Electronic shelf labels solved the first. Loyalty schemes, apps and in-store cameras are being used to chip away at the second.
The price tag became a screen
An electronic shelf label is a small e-ink display where the paper price ticket used to be. It updates from a central system, so a shop can change thousands of prices in seconds rather than sending someone round with a pricing gun. That is genuinely useful for keeping shelf and till in step. It also removes the last friction that kept prices still: changing them no longer costs any labour.
Once changing a price is free and instant, the only question left is what to change it to, and when. That is where the data comes in.
The part that turns dynamic into personal
Dynamic pricing that moves with demand is old news. Airlines have done it for decades. Surveillance pricing is the step past that: setting the price from what the seller knows about the individual buyer, not just the market.
US senators and the Federal Trade Commission have been scrutinising exactly this. The FTC opened a 6(b) study into surveillance pricing and the intermediaries that feed it behavioural and location data. The concern named in that work is electronic shelf labels combined with loyalty and app data that together could support charging different customers different prices for the same item. On this site that is the Kroger and Wendy's case file, and it remains pre-litigation: an inquiry and a study, not a finding.
The worry is not that a price moves. It is that it moves for you, based on what a company has learned about you, in a way you cannot see and cannot compare.
Why you would not notice
A personalised price defeats the one defence shoppers have always had, which is comparison. You can only tell you are being charged more if you can see what someone else is charged. A screen that shows you your price, computed from your data, at the moment you are standing there, gives you nothing to compare against.
That is the same move, in a shop, that the FTC alleges Amazon made online with the pricing algorithm it internally codenamed Project Nessie: raise the price, watch what happens, and hold it where the data says the customer will still pay. Different venue, same logic. The receipts for the online version are in that case file.
What actually helps
Transparency is the whole game. A price that is the same for everyone can be checked. A price computed from your data cannot, unless the law forces the computation into the open. The reason this is worth watching now, before it is normal, is that norms harden fast. A practice that would cause outrage this year becomes the way things are done a few years later, and by then the argument is over.
None of the above is a settled legal finding. It is a documented direction of travel, sourced to a regulator study and a Congressional inquiry. The point of writing it down is so that when the shelf edge lights up, you know what you are looking at.
The case files behind this
Claims described in matters that are still in litigation are allegations, not findings, until a court resolves them. See the evidence framework.