Imagine you are shopping in your favorite grocery store. As you approach the dairy aisle, you are sent a push notification in your phone: “10 percent off your favorite yogurt! Click here to redeem your coupon.” You considered buying yogurt on your last trip to the store, but you decided against it. How did your phone know? Your smartphone was tracking you. The grocery store got your location data and paid a shadowy group of marketers to use that information to target you with ads. Recent reports have noted how companies use data gathered from cell towers, ambient Wi-Fi, and GPS. But the location data industry has a much more precise, and unobtrusive, tool: Bluetooth beacons.
Source: The New York Times