A site was created for Enrique Urbizu’s multi award-winning La Caja 507 before it was released, containing all the information about the film. Also on this website, a short story game-competition setting out from the question “What could be in la Caja 507?” (What could be in box 507?, based on the film title) was created to generate interest. The user had to work out the clues. Each of the clues was associated with a word and all the words served as a basis for writing a short story.