Genre Research

One of the most important aspects of marketing a film is knowing the genre of the text and the conventions that go with this. Every genre is different: Comedy, for instance, is a broad genre, but within it the audience expects the film to be funny. Therefore comedy films will do several things to their posters or any magazine covers to show the humour in one image. It might be that the main actors are in a comedic pose (See the poster for Dumb and Dumber, or the The Muppets as examples) or they may use different genre conventions in a different way. For instance, The Waterboy shows the main character in a stadium, like a poster for a sporting drama, but with a bucket in one hand. A Poster for Anchorman: the Legend of Ron Burgundy, meanwhile, is a take on many local American news broadcasters, who would advertise their shows in similar ways.

While the conventions of a Comedy is fairly straightforward, as other genres like Action or Sci-Fi, the conventions o a Thriller film is not so clear. I essence they have to 'thrill' the audience, hence the name, but by definition, surely if a film was 'thrilling' the term would apply to any film that audience member found enjoyable or exciting. But in essence, that is all thriller films do: provide excitement in films through suspense, tension and uncertainty. This is why so many Thriller films will have a plot twist or leave enigma's right until the end of the film.
There are also many sub-genres to the thriller genre. Psychological thrillers are designed to show mind-games and the main theme's relate to the mind. A good example of a psychological thriller is Memento, where a man suffering from a special type of amnesia tries to hunt down the man who gave him his condition and killed his wife. To add to the confusion, the narrative of the film is not chronological, jumping back and forth in almost the same way as the main character's condition is described (he only remembers the last few minutes of his life). Another example of this sub-genre is Shutter Island, which feature's Leonardo Di Caprio as a man hunting down an escaped prisoner in a lunatic asylum. Apart from the overlaying theme of the mind, there is no distinct character type, although in this sub-genre the characters may have an unknown or hidden backstory, which and be struggling with their identity.
Other sub-genres of thriller's include 'Crime Thriller's' which include film's like the Departed, or Zodiac, where either the antagonists identity is unclear, or there is double crossing by either one, or both sides, and techno-thriller's, where technology is one of the main causes for the problems face within the film, such as I, Robot . The characters aren't as clear cut as 'hero' and 'villain' which is the same for most thriller films.
Many directors past and present are renowned for their work in this genre. Almost all of Alfred Hitchcock's films are critically acclaimed thrillers, such as Psycho, the Birds and Rear Window, and more recently Christopher Nolan who made Memento and the updated Batman trilogy.
Essentially, Thriller films will place the protagonist in danger, often their past being hidden or false, and many of the enigma codes aren't revealed until the end of the film. None of the characters are completely good or evil, and there may be a social issue as a subtext.