Defining "Commercial" vs. "Literary" Fiction
One trope suggests that commercial fiction is plot-driven and literary fiction character-driven. But I see their difference at a structural level:
In commercial fiction, story is all-important; the structure, from sentences to chapters, is designed to keep you turning pages quickly. J.K. Rowling does this so well that in the last Harry Potter book I failed to register a much-noted revelation about Dumbledore - I was reading so avidly that the details evaporated.
The words and phrasing of literary fiction call attention to themselves. Writers such as Thomas Pynchon and T. C. Boyle use words you're unlikely to know. Either you pause to look them up, or miss the point. This sort of thing can be a gimmick - a chapter seemingly constructed around the use of an obscure word - but I appreciate their efforts to expand my knowledge.
Writing in the vernacular, though frowned on by writing instructors, is a marker of literary fiction. I wonder if Jaimy Gordon's novel Lord of Misrule would have won the 2010 National Book Award without the phonetic spelling mirroring each narrator's vocal style. You almost have to read it aloud, which slows you down, which makes you savor a story and remember it longer.
Unusual use of punctuation is another way of establishing Voice - an example is Tom Wolfe's Electric Kool-Aid Acid Test. I find his playful use of colons helps re-create the wildness of those early heady days of psychedelics.
I've been chided for my use of dashes - and finally noticed where I picked up the habit: I gave Ernesto a copy of one of my all-time favorite books, Little, Big, and for the accompanying card, I leafed through to find a quote. And there were the dashes, a whole population of them - I can't tell you how delighted I was, or how vindicated! Knowing John Crowley uses them, I feel less alone, less out-on-a-limb with my writing style.
Sentence length is another show-stopper. Ernest Hemingway's short declarative sentences and straightforward strings of phrases linked with ands, are far more accessible than Henry James' comma-laced concoctions. The latter is probably only read by English majors any more, which is a pity - I find that his sentences begin on the edge of a subject then circle around, phrase by phrase, gradually reaching a focal point - by the time he gets to the nut of his sentence, I know exactly where I am.
Very long sentences compel careful reading, for example Leonid Tsypkin's Summer in Baden Baden, a retelling of Dostoyevsky's The Gambler. A single sentence can run a page or more, but this is no stylistic gimmick - Tsypkin evokes in the reader a visceral empathy with the obsessed young man hopelessly in thrall to his gambling addiction, whose notions of luck and sensitivity to the humiliations of his daily struggle, are made more vivid by the particularity of each sentence.
The cadence of commercial page-turners eases your way forward, flowing smoothly, while the interruptions (what's that word mean? what did she say? etc.) of literary fiction slow you down, inviting you to savor the unfamiliar.
Your reading pleasure needn't be either-or - sometimes, the perfect book is a romance or mystery. At other times, the play of language is just the thing.