quality:corruption
Preserving story secrets

Even if they do not mean to, advertisers, reviewers, scholars and aficionados sometimes give away details or parts of the plot, and sometimes—for example in the case of Mickey Spillane 's novel I, the Jury —even the solution. After the credits of Billy Wilder 's film Witness for the Prosecution, the cinemagoers are asked not to talk to anyone about the plot so that future viewers will also be able to fully enjoy the unravelling of the mystery.