Jaws

From this film poster we can instantly tell that the film is of a horror genre due to the fact that we can see the attacker, a shark with ferocious-looking jaws heading in the direction of a stereotypicall helpless damsel in destress. The fact that the film title (written in blood-red) is named 'Jaws' also signfies to the view that the film sif going to involve jaws (of a shark) and is probabaly going to be quite gorey.
The subtitle at the top of the poster confirms the audeiences's idea that the film is going to be scary in the way that it is the 'terrifying number one best sell' which in a lot of people's eyes means that the film has a guaranteed scare factor!
Below the main frame in the center of the poster is three names of well-known actors which some people will recognize from previous films and will want to see.
We can tell from the shark and the sea and light/dark blue colour theme that the film is going to be set out at or a least near the sea which may attract peopel to watch the film.
People, when looking at the poster may be attracted to see the film in the way that they may feel that the shark is absoloutly massive compared to it's prey and so the film may tell an interesting tale of an epic struffle between good an evil; between man and and this beast.