I don’t know if they still do this but I understood that at some point retailers were using Bluetooth and WiFi sniffers to track shoppers throughout stores so combined with variable pricing they can extract ever more from each customer
I don't know the current status on this, but it worked by recording your phone's mac address (or bluetooth address) when your phone scans for wifi networks. So it could track you without you even needing to join the network. AFAIK this particular tactic was countered by Android and IOS randomizing the mac address it sends out (your networking stack can simply lie about it).
I don’t know if they still do this but I understood that at some point retailers were using Bluetooth and WiFi sniffers to track shoppers throughout stores so combined with variable pricing they can extract ever more from each customer
I don't know the current status on this, but it worked by recording your phone's mac address (or bluetooth address) when your phone scans for wifi networks. So it could track you without you even needing to join the network. AFAIK this particular tactic was countered by Android and IOS randomizing the mac address it sends out (your networking stack can simply lie about it).