Remember that a patent is not a license to do something, it is a license to stop others from doing it.

Amazon can use this to prevent physical stores from doing this.

Kind of pointless since I don't use retail stores Wi-Fi and one can easily turn off Wi-Fi even if someone does and use cellular data.

I wonder if they will block cell signals?

I've noticed in certain Walmarts my signal won't work no matter where I am - more than likely the thick walls I would assume were blocking the signal not some malicious attempt to stop me from price matching.

If stores got truly desperate, they could block cellular signal in stores and provide open, free Wi-Fi. I already can't get signal in most grocery stores, since they're huge and seem to have Faraday cages built into the walls.