One example is biscuit manufacturing, where it’s a fairly open secret that supermarket own brand biscuits are the same product as name brand, because it’s better to capture that segment at a lower margin than to lose it to competition.
Tech now makes it possible to target individuals rather than demographics, but there’s nothing inherently against the status quo in doing so.
I’ll gladly take all the free alcohol an airline will give me, but other people don’t at all!
I sell some stuff on eBay. If you appear untrustworthy, I’ll spend more for tracking/better tracking on your order so you’ll actually get your stuff faster/more reliably.
Price segmentation was more palatable a few decades ago, but technology has enabled us to push it to this absurd (to me) extreme where individuals get different prices at different times of the day.
It feels wrong to size up your customer and pick the highest price you think they'll pay.
.... which, in the day and age of facial recognition, gives me an idea for a startup.
When you're using that fake email be sure to have a burner phone or public internet so they can't link it to your IP, also don't use your computer or any computer you've logged in on so that browser fingerprinting doesn't tag you, also turn off your GPS so they can't geo correlate you.
Of course the rich person is in the same boat, their geolocation will log that they went to Burger King, or their credit card company will snitch on them. Okay, fine, pay with cash, cover your phone in a tin foil faraday cage. Now you also will need to drive a 30 year old car to said establishment since the car manufacturer put a cellular modem and GPS in your car and sells the fact that you went to Burger King to the highest bidder.
That's all I can think of off the top of my head, I'm sure there are dozens of other ways people are tagged. At some level may as well either use the app or just not go.