Signals emitted by your smartphone leave a digital trail that retailers can follow to find out how long you lingered in front of a sales rack or languished in a checkout line.
A growing number of mobile analytics companies use the Bluetooth and Wi-Fi beacons broadcast by smartphones to help retailers monitor customers’ movements in shopping centers, casinos, restaurants, hotels and airports.
One such company, iInside of Yorba Linda, Calif., boasts on its website that its sensors can pinpoint a customer’s location within a single meter of floor space.
On a larger scale, mobile carriers such as Sprint, AT&T and Verizon also use location data gleaned from cell towers to send ads for nearby businesses to customers’ phones, for example, or to prepare marketing reports on how many subscribers visit a city’s football stadium – and what kinds of apps they use during the game.