If you aren't familiar with it, he takes a lot of the work Joseph Campbell did on myth (such as in his book "The Hero With a Thousand Faces") and applied it to writing (fiction as well as movies).
If you consider yourself a serious, professional writer and don't have a clue who Joseph Campbell is, come here. *wiggling finger at you* No, closer.
Noooo, clooooser.
*smack!*
Okay, that's done. Now first thing, you need to familiarize yourself with Joseph Campbell's work. Long story short, he broke down storytelling throughout the ages into commonalities that make them applicable regardless of culture, etc. (That's a very simplistic overview. Go. Read. The. Book.)
Vogler's work takes Campbell's work to a new level, using real-life examples of popular movies to show his examples of the different archetypes of characters and their journeys.
What's cool is while I was familiar with Campbell, I hadn't done a lot of research into applying his approaches to my writing. And as I'm reading Vogler's book, I can see how I have, unconsciously, used the very same archetypes. (Thus proving Campbell's point of a sort of universal unconscious in regards to storytelling. Almost a Jungian theory as well, talking about the archetypes. Please don't tell me you don't know who Jung is. Go look him up.)
For example, in my book "Love and Brimstone," I have Taz as the hero (hero is used generically in Vogler's work regardless of gender), I have Rafe as both a shapeshifter and in some ways a trickster and ally, I have Robertson as mentor and ally, Albert as a herald, mentor, and threshold guardian, and even Matthias, the love interest, is more a mix of ally and shapeshifter.
(Note: shapeshifter, by definition in this use, refers to character qualities/actions, not werewolves. *LOL*)
And as I look at my writing, I see the books that seemed to pour onto the page, almost by themselves, are the ones that seem to closely follow the "hero journey" paths. (Which are extremely flexible, not rigid, fixed lines.)
In writing romance and erotica, a lot of emphasis is placed on the hero (or heroes, in case of a menage or GLBT writing) and heroine, and if there's an Alpha or Beta or Gamma hero, etc. Newbie writers ask about, "How much sex should they have by word count?" The truth is, that's irrelevant if you don't have a good, solid story and good, solid characters to build on.
I'm going to peck out a series of blog posts over the next couple of weeks talking about this topic, especially how to avoid "cardboard" characters.
Stay tuned, and Happy Writing.