An actor would play as a character and interact with other people in the area, this could be the customers or even other characters. They could act as characters and at the same time be clerks who would be selling the product in a subtle direction. They would also carry the book (used as http://www.ricohclickablepaper.com/) and then sort of break "their" fourth wall and tell "their" story to customers. In this way "both" the "character" and the "customer" are able to interact with each other.
What is the core principle of your idea?
"To be in the world of the story by being with the characters". We usually identify with the characters in a book and a great way to introduce one is to meet one. The digital content or e-book is represented by the actor as a character along with the physical book or flyer or print he is carrying with him or as a sticker on him. The characters would carry books or clickable contents, which can be used by the customers as clickable contents http://www.ricohclickablepaper.com/.
Can your idea be applied to different formats (in a bookstore, at a trade fair, at a conference)?
Would it be possible to turn your idea into a reality, or at least create a prototype of it, at short notice, i.e. by the Frankfurt Book Fair in October 2014?
What do you estimate the costs for the prototype or the final implementation of your idea to be?
The price of hiring or renting an actor, or just asking/training current clerks to act as characters of the books.