It's called beacons. Some retailers use it, notably and most recently Starbucks, which used it to better organize their stores to foot traffic. They did not ask people for opt in though and it got a little dicey on the legal front. It's typically not user identifiable (unless you register) and this instance probably used wifi anyways to send a push message.


Sent from my iPhone using Tapatalk

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth