THEORY -> WHY?

Marketing the film is an enormous part of the film's success. There are many elements in the process of a marketing campaign for a film including the teaser and official trailer, to bus stop posters (adshells) and huge billboards advertising a movie. As a result of our modern society and technology, campaigning for this movie also extends to online work through social media such as facebook and twitter. This allows actors from the movie might show small sneak peaks of behind the scenes. The main concern is, without all of this, marketing a film is unlikely to be successful in the box office. The key important reason of a trailer is that it's created to mentally grab the attention of the public so that the production companies can earn money.

When using trailers to grab the attention of the audience the marketing campaigns usually try to interest a large audience which would allow them to gain the peak profit from the movie. Usually when the trailer is released it contains trends and elements that their target audience would be familiar with which would interest people further. However when releasing these trailers, the production company can't just make it like any other feature film trailer as to grab the audiences attention, they need to make the trailer have a USP (unique selling point).