I loathe this writing tip/trope. It's fine as a rule of thumb but I see it way too often than necessary. Screenwriters fucking love it. How many films have started with a high-octane flash-back or flash-forward, but everything that follows comes in a totally linear timeline? Honestly it's borderline offensive. I'm watching your fucking movie, do you really distrust your audience so much that you think they'll just say "fuck it" after the first five minutes? You too, Netflix. Throwing some titties into the opening scene of a show (cough Working Moms cough) doesn't sprinkle some magical panacea on your show that makes people watch it more in case there are more titties. If I want to know whether Maureen gets her tits out again I'm not sitting through a show I don't like to find out. The internet is very adept at informing me of these things.