Why genre is an important factor of filmmaking

We all know that films have certain factors in them which are important when beginning to write a script or start to make a film, the most obvious one being genre.
Genre is an important factor as it not only helps the audience but also the filmmakers.
Particular genres usually include certain codes and conventions like horror films having lots of fast paced editing and high key lighting at certain points and low key at others as well as various other techniques that may be used and recognised of that particluar genre film.
This ability to decifer one type of film etc from another helps the audience by enabling them to decide before going to see a film whether they think they will like it or not as they know roughly what to expect and so they can also give preference to types of film they would like as opposed to those they wouldnt. Being able to place a film within a genre also gives the audience some understanding of the film as they already have a picture of the types of techniques generally used even without realising it.
Genre is also important to producers as it enables them to reach specific audiences by incorporating elements of specific genres but also to reach wider audiences as well by using conventions of various genres to make it appeal to a wider variety of audience members. It also allows them to be able to pick specific roles for actors actresses as certain actors/actresses are now recognised for the types of roles they play in specific film genres. Genre also helps filmmakers as they know what is and isn't acceptable for specific film types and they also know whether to use the typical conventions or to challenge them, this also leads to the fact of do they play it safe and make a smash hit because they know the styles audiences like or do they challenge those theories.
And so genre is reliable for making films or breaking them but also helping audiences and filmmakers make decisions about the films. Especially in terms of making the money from a film genre is particularly important. However it is also important to remember that there aren't specific genres that films can be placed into as now many are being merged into hybrid-genres or films are becoming sub genres from other genres.