Technology Turns to Tracking People Offline

Following people online, with cookies, tagged pixels and even voluntarily given information, has been a big business. Now much of the same technology is moving into the physical world. A company called Euclid Analytics uses the Wi-Fi antennas inside stores to see how many people are coming into a store, how long they stay and even which aisles they walk.

It does this by noting each smartphone that comes near the store, feeding on every signal ping the phone sends. Using the information, retailers can tell whether someone walked by the store, whether a customer came in and how long the visit lasted. If it is a big store, with a couple of Wi-Fi antennas, the owner can start to see where in the store someone went. Euclid is three years old and has about 100 customers, including Nordstrom and Home Depot. It has already tracked about 50 million devices in 4,000 locations.