I don't know if this happens in other countries, but in the UK you occasionally get TV spots where they have mini-interviews with members of an audience who've just watched the film. So it'll be filmed in a cinema lobby and be like "What did you think of the film?" and there'll be a family of four going "Oh it was great, really funny, just perfect for all the family!".
When you see one of these you know it's going to be absolute dogshit.