Back in the early days of smartphones (iPhone, iPhone 3, iPhone 3GS era), Marshall Field's flagship department store in Chicago experimented with this.
Each display window had a bunch of stickers on it, similar to QR codes. You could use the app on your phone to point your camera at one of the stickers and get more information about different products on display.
They also tried something similar with a different app and some kind of Bluetooth connection.
All of this was still early days, so it didn't work very well. It would probably be OK now that the technology has matured.