Movie trailers today are kind of a strange beast. They seem to be designed only to optimize just one thing: getting bums on seats for the opening day of the film. You'd think the smarter long-term strategy would be to set appropriate expectations about the film, and thereby enhance enjoyment of those who do go, to create positive word-of-mouth and generate future patrons. But sadly, that's not the usual case. The result: mystifying spoiler-laden movie trailers that routinely portray a film that's very different to what you eventually see on-screen.