Genre Research: What does this word mean?

Steve Neale has said that "genres are instances of repetition and difference" and this is basically true. Genres in film have adapted from instances in cinema that have been proved popular being recreated to gain a high amount of money again. For instance, Charlie Chaplin was massively popular, so they made more Charlie Chaplin films until basic forms of the Hollywood etc. we have today realised that having different actors doing the same thing would get the same money in, because an audience existed that enjoyed watching people slip on banana peels. This is a process that has spurred on multiple other genres in the same way; if a two minute film full of creepy dark shadows goes down a hit, more production companies will be willing to invest in a three minute film of low key lighting and characters sneaking up on people because they're more likely to make a profit out of the investment.
       Their becomes a point, however, that difference in the repetition creates something that isn't quite what the audience was originally interested in and subgenres were created. Although this is more complicated than someone asking what would happen if you gave Charlie Chaplin a bigger mustache, meaning their can be complications in where a genre ends and a sub-genre begins, similarly seen in how action-adventure has merged into one. Put simply sub-genres are identifiable sub-classes of genre with their own codes and conventions. Fundamentally, however, sub-genre created the opportunity for fans to be even more certain on the sort of films they wanted to see and in turn opened up producers into a more specific target audience. This is an evolution clearly scene in the horror genre that split into slashers, supernatural, zombie, occult and science fiction films that still carry codes and conventions of the main horror genre.