The film storyline is a big part of whether the film is successful or not. A storyline that appeals to a wide variety of audiences is more likely to be a hit, it also needs to be a storyline that the audience can relate to or in order to escape from reality.
Films that are originally books, comics or plays are usually successful at the box office as audiences already know what to expect because they liked the book for example.
Sequels are also successful as they have already got a built in audience for a follow-up film, however this could be a box office disaster as it is known for films to decrease in quality as the sequel continues and fail to live up to the success of the first film. For example, Basic Instinct made $352,700,000 overall, but Basic Instinct 2 made only $38,509,330 which was a box office flop.
Famous actors play a big role in a films success, if an actor has a large fan base, those people are more likely to watch the films they are in, the actors also promote the film by attending interviews and premiers. Brad Pitt is one of the most famous actors and the success of the films he is in links to his popularity, all of the films he has been in have been box office hits. (Fight club, Mr & Mrs Smith, Seven, Oceans eleven/twelve, interview with a vampire and many more.)
A well known director is another important element. A director with a large amount of cinema success have experience and know what attracts an audience, they would also be famous for the films they have created, promoting their current films.
The budget of the film and the film production costs total to a large amount of money. Having an expensive budget can be negative as well as positive. The more money spent on production will create a bigger success for the film as there will be more special effects, increasing the quality. On the other hand, if the film is a box office flop, they wouldn't have made back the money they spent on the promotion stages. An example of this is 'The adventures of Pluto Nash' Their budget was $100,000,000. Within the first weekend they made $218,200,900 then overall made $4,420,080; which was a massive box office bomb.