I just finished reading Neil Gaiman's American Gods. It's terrific, and I won't review it, because it's prize-winning and best-selling and much-reviewed and you can go read what other people have to say about it if that's what you're looking for.
What I want to do is discuss the following question: what drives this book?
You should read the book if you haven't, so I'll try to minimize the spoilers.
It isn't a character-driven book. The protagonist, Shadow (a childhood nickname; we never learn his real name in the novel) has less personality than any other character in the book. He is sympathetic because he is unlucky--he does time in prison that he doesn't really, we are led to feel, deserve, and his wife dies early in the book in circumstances that are quite painful for Shadow--but he is passive until quite late in the story, simply following the directions of his boss Mr. Wednesday, standing on his mark and speaking his lines. He begins to become mildly active about midway through, when he undertakes to find a way to bring his wife back to life, but that's a minor plot thread, and Shadow's real, consequential choices only come at the end of the tale. So I didn't keep turning the pages because I thought Shadow was a really interesting guy, or because I wanted to see how his quest turned out; he's fairly bland throughout, or at least right up until the end, and he doesn't have a quest. He takes orders.
It isn't a plot-driven book. There is a plot, and it's a cool one, but it isn't clear what the plot is, again, until quite late in the story. For most of the book, the plot appears to be that Mr. Wednesday is trying to rally a set of old fantastic characters to fight off a set of new fantastic characters, and Shadow follows him around, doing what he's told. There are subplots, and they are fun, creepy and fascinating as they should be, but they remain subplots, sideshows. I didn't keep turning pages to find out whether Mr. Wednesday could defeat Mr. World, and I didn't keep turning pages to find out whether Shadow would bring his wife back to life, or end up with Sam, or if the missing children of Lakeside would ever be found.
What drives American Gods is its milieu. American Gods is set in what Greil Marcus, in writing about Bob Dylan, called the "Old, Weird America", the America of tall tales, small towns, culture heroes and (to borrow a British term) follies. Gaiman weds that to the mythology of America's various immigrant cultures and pits it against divine personifications of modernity (the goddess Media, and the gods Railroad Baron and Internet, for instance). The result is a really, really interesting story world that kept me turning pages right up to the end.
Milieu-driven books are relatively common in speculative fiction (fantasy, science fiction and horror), and relatively uncommon elsewhere. For instance, just looking quickly at my bookshelf, I would identify The Lord of the Rings, Burroughs's Mars and Pellucidar books, the Gormenghast trilogy, Ringworld and its sequels, Dune, The Runelords and Mistborn as being primarily milieu-driven. That isn't to say that Titus Groan doesn't have interesting characters, or that Ringworld is plotless, but that the principal thing that keeps readers' attention as they read each of those books is the world the author has created.
I like to think about what drives my stories as a writer because I think it's important to play to my strengths. If I am trying to fascinate readers with an exotic setting, then I need to make sure, in writing and in editing, that it's really exciting. If I want to seduce the audience with my characters, I aim to make them really interesting, sympathetic and proactive. And if my plot is the thing, I want it to twist, turn and gnarl like nobody's business, obviously to the reader and right from the start.
Homework assignment for writers: what drives your story? What do you need to do, in writing and in editing, to play more to your story's strength?