Customers can get a tactile experience trying on glasses at Warby Parker's shop in New York City. Elise Hu/NPR hide caption

itoggle caption Elise Hu/NPR

A Nordstrom salesperson shows a customer an online selection of shoes on an in-store iPad. Like some other retailers, Nordstrom is using mobile devices to make on-the-spot sales and check companywide product inventory instantly. Courtesy of Nordstrom hide caption

itoggle caption Courtesy of Nordstrom