The function is to get incremental sales (and hopefully establish a pattern of repeat business) by discounting selectively to people who might not buy at all otherwise.
If you're thinking "But they should give that discount to everybody!" that's not a thing. There's not enough margin in the first place, especially at a supermarket or Walmart, that everyone could just have lower prices on everything.
My grocery store already sends me individualized paper coupons every month.
All of this is promotions. It's all just trying to get some incremental sales, and hoping that if you get an offer for free hot dog buns you'll also buy the hotdogs.
Some particularly skeevy car dealers were skewered many years ago for saying "Advertised price is less tax, title, and additional $2,000".
But they CAN get away with saying "The $8.99 burger is $11.99 unless you: - possess one of a range of sanctioned devices - have access to data services - are able to create and manage an account - are willing to opt in to whatever tracking/marketing gimmickry - can claim the "deal" in advance
Each of those steps is a funnel that opts out at least some potential customers from the deal. The 12-year-old who doesn't own a phone can't get the deal. The 85-year-old who can't operate Android can't. The person making impulse purchases and not pre-researching their meal selection misses the offer.
I feel like there's a argument for a precedent akin to "no purchase necessary to enter" for sweepstakes-- no additional purchase, software install, or commitment should be required to claim any advertised offer.
Strange how this totally worked until a few years ago. I never cut coupons or any other time wasting shenanigans, but was able to stop up on deals on the commonly used shelf-stable items I buy without even needing to signup to a loyalty program.
I understand price segmentation is a thing. But it's gotten pretty exhausting and only increasingly so.
Fast food you can simply opt out of. My health improved due to them shifting all the "deals" to the app, and doubling menu prices. Groceries are a different thing.
This isn't even a little hypothetical- bluetooth had to anonomyze the MAC address to stop this, and it still fails sometimes.
https://nypost.com/2026/04/21/business/jetblue-x-post-sparks...
I also think this hypothetical "scan to see your price" scenario is a lot worse. As things stand now, there's still a baseline price. If the shelf says $8.99 then you know that you may be able to get a better price through their loyalty program or with a coupon, but it will never be more than $8.99. In a fully dynamic pricing world where you have to scan scan to get a number at all, which is what a lot of businesses would really love to have, you'd lose that baseline. That item might ring up at $20 if the system decides I'm desperate or inattentive or just don't care. This is already possible online, of course. If it spreads to grocery stores, though, I'm going to start channelling Ned Ludd and it won't be pretty.