Robinson Meyer just tweeted,

Now that’s interesting. Nordstrom’s website is about as illuminating about all this as you might expect: “If you have a Wi-Fi equipped phone AND Wi-Fi is turned on, Euclid’s sensors collect your phone’s unique MAC address (in hashed form only), manufacturer, and data that is used to estimate its location in relation to the Euclid sensor. We use this information only to calculate and analyze client traffic based on these signals sent from shoppers’ mobile devices.”

Okay . . . but what does “calculate and analyze client traffic” mean? What kind of “traffic”? What precisely are the “Euclid sensors” analyzing? But hey, you can opt out! All you have to do is find out what your device’s MAC address is and enter it at this page. Easy-peasy.

So: until we find out more about what information Nordstrom is collecting and why, we’d better keep our wi-fi off when we’re in the vicinity of one of their stores. They can’t read 3G or 4G networks — can they?