Big Data Hits Real Life: Brick-and-mortar stores are looking for a chance to catch up with their online competitors by using software that allows them to watch customers 
as they shop, and gather data about their behavior.
By STEPHANIE CLIFFORD and QUENTIN HARDY
Like dozens of other brick-and-mortar retailers, Nordstrom wanted to learn more about its customers — how many came through the doors, how many were repeat visitors — the kind of information that e-commerce sites like Amazon have in spades. So last fall the company started testing new technology that allowed it to track customers’ movements by following the Wi-Fi signals from their smartphones.
But when Nordstrom posted a sign telling customers it was tracking them, shoppers were unnerved.
“We did hear some complaints,” said Tara Darrow, a spokeswoman for the store. Nordstrom ended the experiment in May, she said, in part because of the comments.
Nordstrom’s experiment is part of a movement by retailers to gather data about in-store shoppers’ behavior and moods, using video surveillance and signals from their cellphones and apps to learn information as varied as their sex, how many minutes they spend in the candy aisle and how long they look at merchandise before buying it.
All sorts of retailers — including national chains, like Family Dollar, Cabela’s and Mothercare, a British company, and specialty stores like Benetton and Warby Parker — are testing these technologies and using them to decide on matters like changing store layouts and offering customized coupons.
But while consumers seem to have no problem with cookies, profiles and other online tools that let e-commerce sites know who they are and how they shop, some bristle at the physical version, at a time when government surveillance — of telephone calls, Internet activity and Postal Service deliveries — is front and center because of the leaks by Edward J. Snowden.
“Way over the line,” one consumer posted to Facebook in response to a local news story about Nordstrom’s efforts at some of its stores. Nordstrom says the counts were made anonymous. Technology specialists, though, say the tracking is worrisome.
“The idea that you’re being stalked in a store is, I think, a bit creepy, as opposed to, it’s only a cookie — they don’t really know who I am,” said Robert Plant, a computer information systems professor at the University of Miami School of Business Administration, noting that consumers can rarely control or have access to this data.
Some consumers wonder how the information is used.
“The creepy thing isn’t the privacy violation, it’s how much they can infer,” said Bradley Voytek, a neuroscientist who had stopped in at Philz Coffee in Berkeley, Calif. Philz uses technology from Euclid Analytics, of Palo Alto, Calif., the company that worked on the Nordstrom experiment, to measure the signals between a smartphone and a Wi-Fi antenna to count how many people walk by a store and how many enter.
Still, physical retailers argue that they are doing nothing more than what is routinely done online.
“Brick-and-mortar stores have been disadvantaged compared with online retailers, which get people’s digital crumbs,” said Guido Jouret, the head of Cisco’s emerging technologies group, which supplies tracking cameras to stores. Why, Mr. Jouret asked, should physical stores not “be able to tell if someone who didn’t buy was put off by prices, or was just coming in from the cold?” The companies that provide this technology offer a wide range of services.
One, RetailNext, uses video footage to study how shoppers navigate, determining, say, that men spend only one minute in the coat department, which may help a store streamline its men’s outerwear layout. It also differentiates men from women, and children from adults.
RetailNext, based in San Jose, Calif., adds data from shoppers’ smartphones to deduce even more specific patterns. If a shopper’s phone is set to look for Wi-Fi networks, a store that offers Wi-Fi can pinpoint where the shopper is in the store, within a 10-foot radius, even if the shopper does not connect to the network, said Tim Callan, RetailNext’s chief marketing officer.
The store can also recognize returning shoppers, because mobile devices send unique identification codes when they search for networks. That means stores can now tell how repeat customers behave and the average time between visits.
RetailNext also uses data to map customers’ paths; perhaps the shopper is 70 percent likely to go right immediately, or 14 percent likely to linger at a display, Mr. Callan said.