How important is marketing to a films success or failure at the box office?

I believe that marketing is a vital contributor to a films success or failure at the box office. I think this because there are multiple examples of films that didn't utilise their marketing capabilities and therefore failed at the box office. There are also examples of films that used marketing to their advantage and therefore thrived in at the box office. An example for both of these is Avatar and John Carter. Avatar is the biggest movie in the world at the moment and marketing has helped play a vital role in its popularity. On the day Avatar's 16 minute teaser trailer was released Ubisoft also released a trailer for a video game based on the film and Mattel unveiled brand new Avatar-inspired action figures. All these components helped with the hype of the trailer and got the franchise embedded in the audiences consciousness. Avatar also used social networking to their advantage during the lead up to the release of the movie. They mainly utilised Facebook, Twitter and YouTube as they are the leading social networks. On Twitter they offered free content if you tweeted your name to their official twitter page which enables all your twitter followers to therefore follow them also and apply for the free content. They also had a website which allowed audience members to access trailers, images, background materials and music.