Customers walk out of Street Boutique, parked in Shirlington Village, Va. Street Boutique is a pop-up truck that's similar to the many food trucks in the area, except it sells clothes and jewelry. James Clark/NPR hide caption

itoggle caption James Clark/NPR

Lenox Mall, in the Buckhead neighborhood of Atlanta, used to be the site of a country home estate and is now a traditional indoor mall with two anchor stores. Madeline Veira/Youth Radio hide caption

itoggle caption Madeline Veira/Youth Radio

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