And dozens of other brick-and-mortar retailers, Nordstrom has wanted to learn more about its customers - how much came through the doors, how many were regulars - the kind of information that sites of e-commerce like Amazon have to shovel. So last fall the company began testing a new technology that allowed him to track the movements of customers using Wi - Fi signals from their smartphones.
But when Nordstrom showed a telltale sign clients, it was their follow-up, buyers were baffled.
"We heard a few complaints," said Tara Darrow, a spokesman for the Bank. Nordström completed experience last may, she said, partly because of the comments.
Nordstrom experience is part of a movement by retailers to gather data on the behaviour and mood of in-store Shoppers, using video surveillance and the signals from their mobile phones and applications to learn information as diverse as sex, how many minutes they spend in the candy aisle and how long they watch merchandise before buying it.
All kinds of retailers - including national chains, like Family Dollar, Cabela and Mothercare, a British company, and stores such as Benetton and Warby Parker - test these technologies and use them to pronounce on such matters as the management of the stores change and offering custom coupons.
But while consumers seem to have no problem with cookies, profiles and other online tools that enable e-commerce sites know who they are and how they make their purchases, some hair to the physical version, at a time where the Government oversight - of telephone calls, Internet activity and the supply of postal services - is at the centre because of the leaks by Edward J. Snowden.
"Way on the line," a consumer posted to Facebook in response to a history of local news on the efforts of Nordstrom in some of its stores. Nordstrom said that charges have been made anonymous. technology experts, however, say that the follow-up is worrying.
"" The idea that you are hunted in a store, it is, I think, a little unpleasant, in contrast, it is only a cookie - they don't really know who I am ", said Robert Plant, computer systems Professor at the University of Miami School of Business Administration, noting that consumers can rarely control or to have access to these data. ''
Some consumers wonder how information is used.
"The creepy thing is not the violation of privacy, it is how much they can deduct, said Bradley Voytek, a neuroscientist who had stopped in at the Philz coffee in Berkeley, California Philz uses Euclid Analytics technology, Palo Alto, California, the company that worked on the experience Nordstrom, 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."
However, physical retailers say they are doing nothing more than what is usually done online.
"Brick and mortar stores were disadvantaged compared to online retailers, who obtain the digital crumbs of people", said Guido Jouret, head of the Group of emerging technologies from Cisco, which provides tracking cameras in stores. Why, Mr. day requested, should physical stores not "be able to tell if someone who has not purchased was put off by the price, or was just returned from the cold?" Companies that offer this technology offer a wide range of services.
One, RetailNext, uses video footage to study how buyers navigate, determining, say, that men spend just one minute in the Department of the layer, which can help a store to streamline the disposal of its outerwear for men. It is also different men women and children and adults.
RetailNext, based in San Jose, California, adds data from smartphones buyers to deduct even more specific models. If the phone of a client is configured to search for Wi - Fi networks, a shop that offers free Wi - Fi can determine where the customer is in the store, within a radius of 10 feet, even if the client does not connect to the network, said Tim Callan, Director of marketing for RetailNext.
The store can also recognize the buyers come back, because mobile devices send unique identification codes when they are looking for networks. This means that shops can now tell how customers re