They do put electronic advertising screens in front that collect "anonymous" mac addresses. They also put trackers inside the shopping carts to follow you inside the store. The client-card you use during checkout records your name, address and spending habits.

They don't need to sic a minion to sniff after you. The implication of buying condoms and then visiting the hotel only requires to correlate three tables.

Those advertising screens aren't necessarily compliant with the GDPR.

https://techgdpr.com/blog/wifi-tracking-retail-analytics-gdp... has some background.

https://www.spring-board.info/differences-between-geo-wifi-f... is from a British company which claims to do compliant tracking in shopping centres etc.

> The client-card you use during checkout records your name, address and spending habits.

There's a very good reason why I don't have any such client card and will never apply for one.

The store can track your purchases down to the line item if you use one of those. I vehemently disagree with that.

Also, I pay mostly with cash.