MEMPHIS, Tenn. -- Savvy shoppers love a good deal. These days, loyalty pays off, so customers use retailers' apps and reward cards to cash in on bargains.
What you may not know, is that same retailer is using that relationship to watch your every move both inside and outside the store.
Emily Ballard said she mainly shops online and is used to tracking there.
"I guess I never really have thought about being tracked while you're inside the stores."
"Most people understand that this happens online, I went and I looked at what actually happens in the stores."
Dr. Joseph Turow researches marketing and digital privacy. His new book, The Aisles Have Eyes, takes a closer look at how retailers are watching customers.
"We're talking about special beacons that interact with the app on your phone, special lighting systems that do that, WI-fi, Geo location which actually tracks where you are outside the store."
Turow said you don't even have to use the apps on your phone, for retailers to track you through that device.
According to Turow, just having WI-fi turned on when you walk in the store let's the retailer know you exist. He said unlike with an app, they may not know exactly who you are, "but yes, you can be tracked, that's why companies like to have WI-fi in their stores."
Turow said retailers are using customer data to build profiles and cater to those they consider high value clients.
"Based upon your habits, and the profile they have about you, the store can say 'Hey, how would you like 20-percent off' and the person right next to you won't even get near that."
If you don't want retailers tracking you, Turow said you should shut your phone's WI-fi and Bluetooth off, and to make sure your app is closed.