Netherlands. Almost every major super market chain uses them and dynamically adjusts the prices. Here's an article from 2019 about a major chain intending to change all the price tags that year (Dutch): https://www.emerce.nl/nieuws/albert-heijn-digitaliseert-prij...
It's seem to have finally roughly hit critical mass these days. I imagine it will become somewhat ubiquitous in the next 5 years or so in most of the western world.
Inflation seems to have kicked this into high gear as I'm guessing prices update a whole lot quicker. Plus it's a lot cheaper now to fiddle with dynamic pricing and change stuff day to day based on your metrics.
