Steve Neale argues that genres are processes of systemization, not fixed systems, and that people derive pleasure from genres through both the repetition of conventions and unexpected differences or manipulations of those conventions that shift expectations. Richard Maltby believed that Hollywood's global success is due to its combination of predictable genre elements with subtle variations, as audiences prefer to have a sense of what to expect from a film but also enjoy some level of surprise or unpredictability. He theorized that audiences do not like complete surprises or not knowing what to expect at all from a film.