I've been writing fanfiction for a while, and like everyone, struggled to get more readers. Here are my tips on writing a popular story.
More Reviews, Favorites, and Followers
Every fanfiction writer remembers the rush of getting their first review. Some of us get addicted. I'm here to tell you that you're not alone and teach you how to write a popular fanfic from scratch—not necessarily a good one but popular. Because bigger numbers are always better!
This isn't writing advice—in fact, sometimes, it's quite the opposite. Rather, it's a guide to getting more reviews, followers, and favorites (or, in AO3 parlance, kudos, comments, and subscriptions).
1. Write in a Popular Fandom
Before you even start writing, study the largest fandoms on Fanfiction.net and ArchiveOfOurOwn.org. You'll find that major franchises like Star Wars, Marvel Cinematic Universe, Sherlock, Harry Potter, Naruto, Twilight, and Pokémon retain their popularity for decades. By writing for such a fandom, you're guaranteed a certain number of eyeballs on your story, regardless of its ultimate quality.
On the other hand, most smaller fandoms peak at the release of the movie (or book, game, TV show), then slowly fade into obscurity. No matter how good your fanfic is, if you choose a minor fandom when your goal is popularity, you'll be shooting yourself in the foot.
2. Pair Up Fan-Favorite Characters
Let me clue you in on a dirty little secret: The majority of fanfiction readers aren't looking for brilliant writing or clever plot twists. No, they want to scratch a specific itch, usually in the shape of a pairing—a "ship"—frequently one that didn't sail in canon. Think Harry/Draco or Harry/Daphne from Harry Potter, Sherlock/John from Sherlock, Jacob/Bella from Twilight, and so on. I'll go as far as to say that most readers exclusively trawl their favored pairing tags for new content without ever venturing into the wider waters of fanfiction.
Instead of bemoaning this, exploit it by writing about popular characters. Even better, pair them up!
3. Sprinkle in Tropes
Every larger fandom inevitably spawns its own tropes—often ones that take stories in directions that have little to do with canon. Before you know it, you're reading your 20th story about Harry Potter inheriting a lordship with the help of Gringotts goblins; or Loki whump where he gets comforted by Tony Stark; or one about the Winchester brothers being werewolves in a world of a rigid Alpha/Beta/Omega hierarchy.
It was creative the first time someone came up with the idea. Still interesting the first dozen times someone borrowed it. By the time there are hundreds of fanfics following the same premise, it's become a worn cliché.
Should you then avoid fanfic tropes? Quite the contrary! If your goal is popularity, you must embrace them. By all means, give the trope a clever twist if you can—but even when played straight, it can be a juicy bait for luring in readers.
4. Hook in Readers With a Succinct Summary
Bet you expected this one to be higher. The truth is, no matter how great your summary, it won't help your story get famous if your fandom gets ten visitors a day.
That doesn't mean you should neglect it. Every time you post a new chapter, your fanfic gets pushed to the top of the updated story list ("Just In" on Fanfiction.net) and stays there for a precious few minutes. This is where most of your readers will come from, and this is why your summary must draw attention.
Take your time to describe what your fanfic is about. Avoid repetitive language ("What if...?"). Don't use an out-of-context quote—that doesn't tell potential readers anything. And, for all that is holy, don't write "I'm bad at summaries"—even if it's true.
5. Update Regularly and Consistently
Remember that "Just In" page? Your goal is appearing on it as often as possible—within reason. To this end, post a new chapter every week, preferably on the same weekday. You will see your hits, kudos, reviews, or comments grow with each chapter from your story appearing at the top of the list alone.
If you believe you can churn out more frequent updates without getting burned out, by all means, go ahead! I still suggest spacing out chapters by at least a couple of days because posting more frequently will give you diminishing returns. Additionally, avoid too many chapters under a 1,000 words—unless you're writing poetry or a series of drabbles, that usually carries a stigma of its own.
Above All, Keep Writing
In the end, a lot of it comes down to luck. The weirdest fanfics become famous (or infamous) for the darnedest reasons. Who hasn't heard of My Immortal?
The good news is, fanfiction is a very forgiving medium. Almost every author is an amateur, and many are teenagers with little life experience. There's no need to be self-conscious or insecure. Indulge yourself. Toss the rule book out the window. Three-story act structure? Who cares, you just want to write about Jon and Sansa running a café together! (And chances are, many others will happily read that).
If there's one area you can afford to throw stuff at the wall and see what sticks, it's fanfiction. Go wild.