Genre as a marketing tool

This is a poster for a horror film called 'A tale of two sisters'. You can tell this is a horror film because of various things. One of the ways is the image of two young girls sat on a sofa covered in blood and we would usually associate that with horror films. The critic's quote 'So Bloody Good' adds emphasis on the theme of blood and suggests there is a bloody theme in the film.
Like a typical film poster it has a dark background and a font colour that contrasts the background making it stand out. And as well as this it has a dark and chilling tagline. However it differs from the rest because on horror film posters they would have either just the antagonist or a beautiful girl who is usually the victim.
In this there is like a family posing like they are the perfect family but they look like they have some hidden secrets. The picture of the familly also suggests its a psychological because just by looking at the picture it gets the audience thinking why are the two girls covered in blood? Is one of them a killer? It engages them and creates an interest making them want to go to the cinema to watch it.