These beacons are small, inobtrusive electronic devices that are hidden throughout the grocery store; an app on your phone that communicates with them informed the company not only that you had entered the building, but that you had lingered for two minutes in front of the low-fat Chobanis.
Well that solves the problem. Don't let sketchy apps access your Bluetooth/location
They don't have to be connected to see your device. Just like how Find My Device works by searching for the Bluetooth signal. You'd need to have Bluetooth completely off, so no smart watches or headphones for you in the grocery store I guess.
Exactly, and this is additionally why it is predatory: you can't opt out.
It's similar to Facebook. If you never in your life ever created a profile, well, Facebook has one for you regardless.
The only way you can opt out of bluetooth beacons is to not bring your phone/smart watch/etc, or have either a hardware switch that disables your network functions or put it in a faraday cage. Also, because of data profiles and associations, if you're walking into a store with your partner, expect that your partner should do the same or else it's all moot. You're associated with your partner and thus tracking and profiling occurs anyway.
Add in the facial recognition technology they're also deploying and go to the next level of Dante; what do people's habits who look like "x" who are with people(kids, partners, friends) who buy "y" and don't buy "z"?