NFC tags cost about 20 cents and they are easy to use, tied to a place, etc.

I've done a lot of thinking about cyberphysical art that used to look like

https://mastodon.social/@UP8/111013706271196029

and now look like

https://bsky.app/profile/up-8.bsky.social/post/3lbqfh7pesc2x

Notably with the QR code on the back I found people didn't understand the branding of the card and had to flip it over to know the affordances it offers which didn't work when the card was stuck to the wall, as in

https://bsky.app/profile/up-8.bsky.social/post/3lbftgz6kok2c

I researched NFC tags as an option here and bought a 100 pack and a Sony FeliCa reader but found the problem of "communicating the affordance is available" was much worse, there's no standard logo (except one that belongs to the banks that they wouldn't give me permission to use) and not much awareness. I was irritated that NFC support is limited in iPads, for instance. So I stuck with QR codes that people understand.