wikipedia: A cliffhanger or cliffhanger ending is a plot device in fiction which features a main character in a precarious or difficult dilemma, or confronted with a shocking revelation at the end of an episode of serialized fiction. A cliffhanger is hoped to ensure the audience will return to see how the characters resolve the dilemma.
The phrase I focused on here is "hoped to ensure the audience will return." HOPED. Because I despise cliffhangers at the end of a book. At the end of a chapter? Sure. Then I can get some immediate resolution, but when you're reading the first of a series and you have to wait a year for the answer, it's torture. In fact, I usually feel duped, so I don't even bother getting the next in the series for fear it will try to trick me again. (Fool me once, shame on you. Fool me twice, shame on me.)
I expect that the conflict raised in the novel will be solved by the end of 500 pages. When it isn't; it's frustrating. Yes, I get that you're trying to sell more books, but what I prefer to do is to solve conflict A and introduce conflict B in my last few pages. That will ultimately be the focus of book two, but I want my readers to feel like the time they spent with me in book one wasn't just a build up to something else. (Although, I'll admit, I am a shameless user of the cliffhanger for my chapter endings.)
Q: So, where did this blasted device come from?
A: We can all thank Thomas Hardy. In “A Pair of Blue Eyes,” a novel that was published in fifteen installments in Tinsley’s Magazine in 1873, the main characters literally fall from a cliff at the end of one of these installments.*
And since then, characters have been hanging from cliffs, defusing volatile explosives, catching husbands in affairs, and tearing off weaves all for the sake of dramatic pause for the past 142 years.
But I want to take a poll.
*Source: "Tune in Next week" from the New Yorker.