Years ago we could listen to part of the concert from its poster in Sci-Fi Movies, and now it is really possible. Smart posters are equipped with a tag to provide a wide range of information such as audio, video, phone number, contact information, map or simply text.

Suppose you find a smart poster advertising a new mall somewhere, you can either find the address in bottom of the map or just close your phone to read the address, a small map and a picture of the building even a contact phone. Cool! now we know all we need to get to the mall.
To surprise the seller can offer a discount coupon to those who has read the tag.

To get the idea watch the video showing the function (not by me):