You're wrong, but not about what people want most often. Some of the best stories are tragedies and you're ignoring a ton of historical context in this answer.

I disagree. One of the main reasons why I don't like reading much fiction is precisely that I already know how the book will end by the third page

@David If you don't like reading fiction, you are not in my target audience! The people that buy fiction and LIKE reading for entertainment are the people we write to please, and they like happy endings, especially happy endings that seemed difficult to achieve, because they like righteous struggle that pays off. We write and sell books to entertain people that like to read. Writers and agents and publishers of fiction are giving people what they already find fun and entertaining. We aren't trying to convert people, we're just taking them on an adventure with surprises along the way.

@Amadeus You completely missed the point of my comment. There is people (like me) who would like to read an unpredictable story

@Kirk Yes, I am ignoring history because dead people don't buy new fiction. I am focused on what modern living people want to read. Tragedies; may be highly acclaimed as wonderful writing, but they don't sell very well to the modern audience as fiction. The lion's share of sales are sales of heroes prevailing, not failing. They may lose friends along the way, suffer losses, tragic things can happen, but in the end they prevail. Darth Vader can kill a billion people, but the rebels defeat him. Fame can sell a tragedy, but it still does not sell well to the modern fiction audience.

@David How could you possibly know it was unpredictable if you think you know how it ends on the 3rd page? You are basically saying you have to know the ending before you start reading, and in that case, it is NOT unpredictable. And besides, people read for the plot, and twists, and humor and complications and struggles of an MC they like. Writers assist the imagination and that is the point, they want an adventure, to worry for the well-being of characters (which may in fact die defeating evil), they want to believe in heroes. It isn't about how it ends, it's about how they got there.

I tend to find absurdist wish-fulfilment stories where the "heroes" always pull through in their happy-go-lucky 'struggle' to be profoundly disappointing. Stories where the hero loses, or gains a pyrrhic victory - where the narrative is more important than the victory - tend to be far more nuanced, thought provoking, and interesting. Not downvoting, but as a reader I disagree with the founding principles upon which this answer is based. This is your personal taste, not a universal law. Besides, look at the popularity of that modern Tragedy, "A Song of Ice and Fire"/"Game of Thrones"

@Amadeus If there was a balance between hero/villain successes, then there would be uncertainty when you start a novel. I think you are smart enough to understand my point. I don't know why you try to pretend you didn't. By the way, Galastel mentions in his answer "1984" by Goerge Orwell. Do you think that's a story people don't enjoy reading?

@Chronocidal The question is whether the bad guy can prevail and kill the hero. It is not saying the heroes always pull through, are never in danger, are never injured and never lose anybody they love. Many (maybe most) satisfying stories (for adults) demand heartbreak and losses, emotional trauma. But the bad guys don't win! Even if the hero dies, which is possible, they do so extracting some kind of victory against the villain; they saved somebody they love, or ensure the villain won't prevail. That is not what is normally termed "wish fulfillment". Bad guys win, hero dies will not sell.

@David in most books the hero fails more often than the villain. That is the prescription of the 3AS: Fail, Fail, win, and repeat. Hero fails in Act I, Act IIa, Act IIb, and only pulls it out in the climax by finally learning what they need to learn. When Harry Met Sally -- they both fail at romance the entire story, spanning years, until they finally figure it out in the last 10%. We know from minute 1 they will get together: failure doesn't sell! The story is about how will they overcome the constant obstacles to that? You can't predict that because you don't even know what they are yet.

@Amadeus Great explanation. You are right! That's why George Orwell's 1984 was only read by about 4 people at its time and nobody remembers it anymore. If you do what everybody else is doing, you won't achieve more than what everybody else is achieving! By the way, your entire argument of "that won't sell" is meaningless since people don't know the end before purchase!

@David That is false. Agents and publishers and studios all know the ending before they accept a story; and most people that read books or see movies will warn others if a book has an unhappy ending. Word of Mouth is what sells books/tickets and can kill a book. 90% of people listen to recommendations or pay attention to stars or ratings before they buy, and it is the risk-taking 10% that buy blind and their opinions form the judgment. If they don't like how it ends, they say so, and bye-bye blockbuster. Which is why MODERN publishers and studios dislike unhappy endings!

@Amadeus Word of Mouth has always existed. It can ruin your book, or it can spread the fact that it's the among best ever written. Also, no publisher will dislike the idea of working with one of those. I go back to my previous point: do what everybody else is doing and you'll get what everybody else is getting (and trust me, the amount of writers that become billionaires is way below 50%) Following your advice, maybe the best chance for the OP is to buy some fake reviews.

@David 1984 is fiction intended to make a real world political commentary. It is written in 1949 when the audience is actually worried about totalitarianism and government secrecy and overreach. It was a bestseller because it was taken as a wake-up call of where the actual real world is headed. That is not "entertainment fiction", that is a political movement. If that is what you want to write, sure, write a tragedy, if you are as imaginative as Orwell and can get an entire country talking, good for you. I think it's a far longer shot than writing something that will entertain people.

@Amadeus If you don't intend your novel to be the best ever made, why publishing it at all? Keep improving it until it is!

@David, now you are being ridiculous. You believe as you wish, my answer stands, you will not convince me with childish nonsense like "I should only publish if I think I am the best writer ever born". Conversation over, write your own answer and make your arguments there. I'm done here. Find somebody else to play with.

Well, the most upvoted answers basically agree with me. You can call me a child and/or ignore me all you want, but that won't make you be right. I think your creations should try to get the most out of yourself. If you think you should publish generic rubbish, well, good luck!

BIG BROTHER is not a "bad guy", there is not even an actual character in the story named Big Brother, IT'S AN ABSTRACTION OF TOTALITARIANISM. omg! Villains are from melodrama, not literature. Does anyone even read books here or do they just watch comicbook movies?

@wetcircuit As I said. It is political fiction intended as a warning to society; and it succeeded on that front. It was also inventive and entertaining in that political context; but that doesn't make it a great story, any more than a great advertisement is a great story, or a great thesis is a great story. IMO, if it weren't for its real-world political impact and echoing of real world concerns about the power of governments, I don't think it would be a bestseller at all. It has more in common with Pulitzer prize-winning Journalism than it does with escapist entertainment fiction.

@Amadeus 100% agree. People throw out examples that are just bizarre in how badly they DON'T fit the topic….

O'Brien "wins" 1984. He's as tangible a "bad guy" figure as you can get in a book. Also, why was a Song of Ice and Fire so highly regarded? Even before the show was announced, it was one of the most successful series in the high fantasy genre. And its third book Storm of Swords (the most widely considered "best" of the series) could have "bad guys win" as its synopsis. And it's certainly not like it grabbed people's attention with good guys prevailing in the first book. (In fact, it's the very opposite that gave it its notoriety in the first place.)

@Bridgeburners Does it seem like the story is concluded by the end of Song? Heroes (or groups) have setbacks for most of a story, we expect it, and the death of other good chars, to build tension and raise stakes and prove the actual bravery and courage of the heroes. Good guys can't waltz to victory, Cinderella must suffer hardships to be worthy of the Prince, & he must go on a quest to prove his love. My point is about the ending, readers or viewers expect the evil to be defeated in the ending, they will be disappointed if the hero dies at the end and the bad guys win.

This depends heavily on the genre and target audience. If you were to say that certain genres such as "Sword & Sorcery" are primarily about wish-fulfillment and there is a strong expectation of the "heroes" winning I will agree. Broadly applied, a lot of great literature involves the "bad guys" winning (1984) or at least a heavy price to a victory for the good side. I just finished Peter V. Brett's Demon Cycle. It bordered on "Sword & Sorcery" and the good guys won, but only through a heroic sacrifice at the end and with several other named characters dying before that.

@TimothyAWiseman Heroic sacrifice and death does not mean the bad guy won in the END of the story, and we are talking here about fiction for entertainment, not political or educational fiction like 1984. For entertainment, the good guys winning is what readers prefer, period, they vote with their dollars and the vote is 90 to 10, in books and in movies. Heroes must suffer for their victory to mean anything, thus the loss of others and hardship to the brink of hopelessness. In the modern market if they don't prevail at the end of the completed story, word of mouth kills sales fast.

-1 because people can and will root for a villain if we can empathise with them. Just look at Breaking Bad, it's about a good man turning into a criminal mastermind who ended up killing, directly or indirectly, more than two hundred people. Most people thought his wife, who tried to stop him and generally what was best for the family -- fundamentally, the righteous heroine -- was being annoying!

@FriendlyNeighborhoodDemon And where in Breaking Bad was the hero opposed to the villain that died in the end so the villain prevailed? You aren't talking about the scenario the OP outlined! This question is specifically about the good guy hero we have been following for an entire series failing and dying and the villain he has been opposed to for an entire series winning. Breaking Bad is a different kind of story, a war between bad guys. In the end the bad guy MC has a Pyrrhic victory, killing his enemies and dying too; but ensuring his family gets his money.

What about For Whom the Bell Tolls? It's not a political dystopia. It ends with Robert Jordan dying, and the fascists winning. Did that one not sell?

@Galestel Pyrrhic victory; Jordan blew up the bridge as he planned to do, and to save the woman he loved, self-sacrificed and stayed behind knowing he would be killed. That is not the OP's scenario in which the good guy dies and the villain wins; Jordan both accomplished his mission and sacrificed himself for true love.

@Amadeus George Orwell, while he openly had a political agenda, also sought and succeeded in entertaining his audience. Shakespeare's tragedies were truly commercial ventures and were successful in their own time, but the heroes did not win. Do you have a citation for your numbers of "90 to 10"? In some genres, the hero winning out eventually is virtually necessary. But in others, like tragedies, it is not at all required and many tragedies are commercially successful. And sometimes, it is not clear who the hero is or even if there is one. See e.g. Memento

@Amadeus btw, while dead people don't usually buy new fiction, live people certainly do buy fiction by long dead authors. That's sort of what fame is.