How much is too much in fiction?

Dave White wonders, and I commented:

Any action or event (violence, sex, swearing, smoking...) should be there because it fits the character. If his morals are questionable, his actions ought to be questionable.

You never know what will offend people, but if they separate some action from the story's context or the character's personality and object to it, they aren't really your fans. Real fans would know a character's history. While they may not like the path he takes or where he ends up, both his behavior and its outcome would be plausible to them.

You should be concerned if, as writer, you're asking, "Would/Should my character do that?" Theoretically, a story's limits should be the character's own morals, but if you don't feel comfortable writing past a certain point of violence, sex, etc., you can imply such actions without fully showing them, and you'd probably pass a censor's standards as well.

Dave cited that the writers of Lost welcomed the strike's side effect of giving them a chance to see what viewers thought of the current arc before continuing that storyline.

I commented:

I understand Cuse and Lindlelof's perspective because TV shows have a narrower window than books do to hook and keep an audience. TV writers have to keep viewers consistently entertained each episode, not to mention each season. If viewers object to anything, they can stop watching. The effect immediately shows in the ratings, and the show may get canceled.

If readers object to anything, they can stop reading, but they've already bought the books, and that's the bottom line to publishers. Disgruntled readers may not buy an author's books ever again, but thousands of readers would have to share the same opinion to affect the author's sales. Thousands of readers might agree on what's good (i.e. a bestseller), but I doubt they'd agree on what doesn't deserve to sell, even after reading bad reviews.