Grocery Store Uses LED Lights To Track Customers

John Lister's picture

A French grocery chain is turning its overhead lighting into a way to send special offers directly to shopper's phones. It's seen as a way to experiment with technology, while still serving a more basic function.

The lights are created by Philips and are being tried at a Lille branch of Carrefour, one of France's major chains of food and home goods stores. The entire store has been refitted with LED bulbs.

Unlike ordinary bulbs, these transmit a signal by emitting light at a specific frequency for each bulb. The light can't be seen by the human eye; however, the front-facing camera on a smartphone can, plus it is able to detect the particular frequency - similar to how a TV set can receive commands from a remote control.

Lights Trigger Special Offers

Customers can then use a dedicated smartphone app which not only uses the frequency to pinpoint their location within one meter, but also the direction they are facing. The app then uses this information to work out which section of shelving the user is facing and then bring up details of relevant special offers on their phones.

The idea seems to be that this makes it much easier to run promotions on goods without the need to print and display individual signs. It could even be possible to have offers that only run for a short period during the day; for example, if a store knows it has a lot of fresh lunch-related food left in stock come the afternoon.

In theory, the app could also make it easier for store management to learn more about the route shoppers take through a store, which could affect layout decisions.

Light Waves Could Replace Radio Waves

The BBC reports that Carrefour isn't the only company testing similar technology. Researchers in the University of Edinburgh are looking at ways to use light waves, rather than radio waves, to transmit data at high frequencies over a short distance. (Source;

Meanwhile, several other stores are exploring using Bluetooth transmitters to track customer location and deliver relevant offers. Bluetooth transmitters are cheaper than the lights and easier to install. The big drawback is that they can only measure distance, and thus can only put the shopper within a particular radius rather than find their particular location.

Installing the LED lights is a substantial operation, but does bring benefits even if the tracking technology proves less effective or useful than anticipated. Philips, which makes the bulbs, says they will cut the store's energy use for lighting by 50 percent. (Source:

What's Your Opinion?

Is such a system genuine useful or merely a gimmick? Would you use such an app if the offers were worthwhile? Do you have any concerns about a store tracking your route around the aisles?

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blueboxer2's picture

OK, I'm prejudiced - I am typing this by the light of an LED lamp, with which I am immensely pleased. I like the light, the colour temperature, the low power drain, the brightness and the fact that, barring a medical miracle, it will outlive me. On those grounds alone, I suspect there's an incontrovertible case for any major retail space to re-lamp with LEDs as fast as they can scrape up the money.

As for this new added feature, it sounds like a transformational breakthrough that will be an enormous success. I notice everyone is very quiet about the associate privacy issues but it shpuld be possible to overcome those. A major breakthrough.

Unrecognised's picture

They'll preferentially target people. They'll select only one person and make everything free, using this like a lottery to attract people into the shop.

Lotteries always thrive in environments of economic/other inequality. The more desperate people are, the more grotesque hoopla there is surrounding one single person's relative privilege.

There will be subtle discrimination against individuals not conforming to particular types. Types will be cultivated and used as marketing tools in turn ['the beautiful people shop here'].

There is nothing good in this technology. All it will do is facilitate fine-grained discrimination.