Today is the last part of a series on movie marketing. For the others: Part 1, Part 2, Part 3, and Part 4.

We are fortunate to have an insider’s take on the subject. Our expert, who prefers to remain anonymous, has worked in marketing for one of the big movie studios for 7 years, first involved with specialty /indie-films, then moving up to the studio’s major motion picture division. Today’s questions cover a wide array of subjects including why movie trailers reveal so much of the plot (you won’t like the answer).

Q: When you market a movie, you’re not just competing against other movies, but also cable TV, broadcast TV, social networking, online games, Twitter, etc. What do you consider your biggest competitor for a consumer’s attention when you’re marketing a movie?

A: Our biggest competitor when marketing a film are films from other studios. While audiences pay a lot of attention to other media types, whether it be TV, gaming or social network, there is still nothing that compares to the experience of sitting in a theater and watching a film on a huge movie screen. An audiences mood is infections. There is nothing like watching a horror movie with a bunch of strangers and hearing everyone gasp at the same time.

Q: Pet peeve from GITS readers: Why do movie studios make trailer that give away so much of the plot of the movie they’re promoting?

A: I can’t speak from experience as to why studios cut trailers that give away almost the entire plot of the movie as I’m not on the creative side. My best guess would be that the creative team is doing the best they can to hook the audience with the storyline. Unfortunately, sometimes they just give too much away. I do know almost every piece of creative is often tested among focus groups, and the people in those focus groups give their stamp of approval. So, while I imagine it must be frustrating from a screenwriter’s point of view, the general audience really enjoys knowing the whole storyline.

Well, there you go. They test focus the crap out of their movie trailers and they’ve discovered that moviegoers on the whole — the people who you hope to become the audience for your movie — like knowing the “whole storyline” before they go see a movie.

Q: If you could give screenwriters one piece of advice that would make your job easier to do, what would that advice be?

A: I don’t really have any great advice for screenwriters because quite honestly, I’m in awe of what you do. PLEASE keep writing. You give me a job to do…and you keep me and the entire world entertained.

So no secret formula, no special voodoo from the world of marketing to help steer us save two that we’ve covered already: (1) They like movies with a strong story concept. (2) They like movies that have a clear target audience.

If there are other areas of the movie business you’d like to learn more about, please post them in comments – and I’ll see what I can do in terms of lining up more Q&A’s from professionals.