This is a great article by A-list screeenwriter Terry Rossio about what it takes to keep viewers engaged. Rossio should know. He's penned hits like Pirates of the Carribean, Shrek, Men in Black, National Treasure, and many more.
Rossio contends that the audiences are so sophisticated today that they will see your plot twists and turns coming from a mile away, even at night, without headlights on. Makes sense. Audiences today grew up inundated with feature film-watching: on TV, cable, video store rental, on-demand shows, Netflix subscriptions, pirated bit torrents, and of course, movie theaters. Previous generations were limited to the occassional cinema showing, and (in my generation), a few HBO movies, which we got to watch 57 times a week. And these kids with their vid-ee-yuh games, well, that's just a whole new level of interactive storytelling.
In the past 10-15 years, screenwriters struggled to sell their character-driven stories. Hollywood execs looking for huge opening weekend numbers, poster-friendly tag lines, and lunch box tie-ins just were not interested in "character studies." Like, The Graduate. Or Streetcar Named Desire. Or Casablanca. Well, that one had Nazis, so maybe they'd give it a pass.
What the execs were looking for was so-called "high concept" movies, whose main plot elements could be summarized in a pithy sentence fragment:
It's Gone with the Wind meets Godzilla.
Hmm. I like it. But could it be Rodan instead of Godzilla?
Actually, high concept does not necessarily mean crap, as Rossio points out. But what you need these days, he says, is a second major concept in your screenplay that could almost stand on it's own as a script. If you can put those two ideas in the same script, and make them work believably, you're in business.
The bar has been raised for movie-makers. No matter how good your acting, direction, editing, or cinematography, if you're audience is two steps ahead of your plot, then you're toast. Boredom kills entertainment.
So, as you write your indie opus, just remember: Your audience is plotting against you.