Synopsis research

At one point or another, everybody has impulse bought a film based on its description (usually films found in a local store's bargain bucket). A synopsis has to be snappy, interesting and compelling enough to gain an audience. Having said this, not all films can be judged on the basis of their synopsis. Some films such as Container or the Holy Mountain, can't even be summarised concisely enough to warrant the need for a synopsis.
While some people will watch a film on the basis of it's synopsis, some would argue that it spoils the film. Take a film like The Usual Suspects: while it is certainly an excellent film, part of its appeal and success is derived from the shock of its twist ending, which TV magazines frequently refer to in their description of the film. In the case of films such as Identity, or Vanilla Sky where the twists are integral to the plot, synopses have been known to practically give away the entire story.
I am certain everybody has had the classic 'Oh, you didn't already know Darth Vader was Luke's dad?' at some point, and it is clear that some twists have become so universally acknowledged that they are more likely to be victim of parody than pastiche. Simply mentioning there is a twist involved in a film is usually enough to get them guessing ('It was all a dream. Split personality. ALIENS.')

If we were to attempt to summarise our film in a similar manner, it would be along the lines of: "five characters each showcase different attitudes towards coping with knowledge of their own death", or something fancy like that.