Summary:
Who this article is for:
Authors, publishers, and marketers trying to make content actually spread on TikTok and Instagram Reels, not just post into the void.
Key takeaways:
Niche audiences build virality long before the mainstream notices. Fans need something to make their own, not more content about your product. Character and feeling beat plot and polish, every time.
What’s inside:
Two real case studies (Dungeon Crawler Carl and A Court of Thorns and Roses), the pattern behind both, and a 5-step guide you can apply to any product or niche, not just books.
Dungeon Crawler Carl is a LitRPG novel about a man and his ex-girlfriend’s cat surviving an alien game show, and it became a breakout hit less through traditional marketing than through readers relentlessly passing it to each other. I picked it up because three different women recommended it to me in the same week. For context: this is a genre that has historically skewed about as male as they come. I ended up recommending it to my own group chat with the same energy people usually reserve for Harry Styles ticket drops. It felt like reliving the ACOTAR hype from a few years ago…
…an instinct that honestly wasn’t far off.
Two of the biggest book phenomenons of the last few years got there through the same platform, using two very different versions of the same strategy. I looked into what Dungeon Crawler Carl and A Court of Thorns and Roses did, or more precisely what their readers did with them, because if you’re an author, publisher, or marketer trying to make something spread on TikTok and Instagram Reels, this is the part worth studying: how niche audiences create real momentum, and how fans build content around a product in ways ads usually can’t. Then I turned it into a five-step guide you can apply beyond books, because that’s the point of this post.
Case Study #1: Dungeon Crawler Carl RPG
Author Matt Dinniman self-published the first novel in the ongoing Dungeon Crawler Carl series on Amazon on October 2, 2020 after serializing it online, turning it from a web project into a breakout dungeon crawler / LitRPG property. No publisher, no marketing budget, no plan. Ace Books (an imprint of Penguin Random House) didn’t acquire print rights until 2024, well after the series had already built its own audience.
By mid-2026, as of May 2026 eight novels had been published, and the series had sold more than 10 million copies across those books. The first book spent 19 consecutive weeks on the New York Times bestseller list, and the first novel alone had sold over 2.7 million copies by then. The stat that explains the BookTok crossover, though, is the audiobooks: narrated by Jeff Hays, they’ve logged over 140 million hours of listening on Audible, the seventh installment’s audiobook reached #2 on The New York Times list, and a separate Audio Immersion Tunnel adaptation helped broaden the format appeal even further.
LitRPG is built for gamers and tabletop fans, not romantasy readers. But a dungeon crawler is a subgenre of role-playing games, and this one drops coast guard vet Carl and a prize-winning show cat into a trap filled fantasy dungeon that runs on video game logic inside a reality television show engineered as a sadistic intergalactic game. Carl Donut works because their partnership is central to the narrative, and Donut grows from pampered pet into a powerful ally. BookTok’s fantasy and romance crowd found it anyway, fell for the humor and the found-family cast (Princess Donut, the cat, especially), and recommended it the way that community recommends things: loudly, repeatedly, and to people who had zero interest in gamer-lit until that moment. “If your wife won’t read Dungeon Crawler Carl” became its own trend format on the platform. Readers were getting everyone in their circle, men and women alike, to promise they’d read it too.
The appeal wasn’t just premise: the main characters, Carl’s humor and resilience in crises, and the series’ mix of absurdity and cleverness — often with dark, lowbrow humor — gave readers something unusually easy to pitch to friends.
The book has been out since 2020, though, and it didn’t explode until this year. For four years it built quietly through Royal Road, self-published Kindle sales, and word of mouth on Audible. Print edition releases also include bonus material exclusive to print, including an exclusive bonus story and bonus novella tied to Pineapple Cabaret. The mainstream payoff arrived in 2025 and 2026. In November 2025, Books-A-Million named it the inaugural winner of their Book of the Year award; the VP of Marketing behind the pick said she’d personally converted more than 70 people, “from coworkers and gym friends to Facebook acquaintances I hadn’t spoken to in years.” In June 2026, Peacock greenlit a TV adaptation with Seth MacFarlane’s Fuzzy Door producing. Renegade Game Studios also announced a tabletop rpg, its crowdfunding campaign raised over $4.5 million, and Playmates Toys is producing merchandise including toys, figurines, and trading cards. The webcomic adaptation launched on July 17, 2025 through Vault Comics, its first volume was published in May 2026, and Dungeon Crawler Carl: Crocodile is an upcoming graphic novel following Florin DuPont. A tabletop card game tied to the series blew past its $250,000 crowdfunding goal, closing at $13.3 million from more than 56,000 backers.
That’s six years of word-of-mouth compounding before the mainstream noticed. Along the way, the fandom got specific enough to shape a real casting decision: when Peacock cast the show, Princess Donut’s voice went to Jeff Hays, the audiobook narrator, instead of a name actor. A studio picked the voice its own audience had already decided was correct.
The takeaway: a niche product doesn’t need a mainstream audience to have a mainstream moment, and that moment can show up years after launch. It needs the right niche audience to connect with it hard enough that they start marketing it, for free, to people who were never the target demographic. The rest is just time.
Case Study #2: A Court of Thorns and Roses
Sarah J. Maas probably doesn’t need an introduction if you’ve spent any time on BookTok, but the numbers are worth stating plainly. Through mid-2024, she’d sold 4.83 million print copies across her series, more than the next four bestselling BookTok authors combined. She’s credited TikTok directly for the growth.
What’s more interesting than the sales figure is what fans built on top of it. There’s a fan-made instrumental called “Luminary,” written and posted by a single TikTok user, that the community adopted as the unofficial ACOTAR theme song. People request the sheet music. People post “explaining the lyrics” videos for an instrumental track that has no lyrics, made by someone with no connection to the publisher. It became canon because enough people agreed it should be.
Then there’s #BatBoys: Rhysand, Cassian, and Azriel, branded online as “the holy trinity of trauma, wings, and smirks.” Fancasts, ranking videos, “meet the Bat Boys” intros, entire accounts built around the bit. No one at the publisher approved any of it. Readers decided the series needed a soundtrack and a boy band, and built both.
The takeaway: the goal isn’t producing content about your product so much as giving readers a foothold to build their own content around it, the kind you’d never think to make yourself. A theme song someone else wrote. A nickname that sticks. That kind of thing outlasts anything you’d publish on your own.
What these two have in common
Neither book took off because of a flawless ad campaign. Readers connected with a feeling or a character before they cared about plot. Fans got something they could genuinely claim as their own, not a hashtag a marketing team invented. And the whole thing ran on being unpolished and real, which is usually the hardest thing to fake on purpose.
So what does this mean for you? Whether you’re trying to market YOUR book, a different product, or just interested in learning about viral marketing tactics, here’s our guide to consider:
5 Steps to Make Your Book (Or Almost Anything) Go Viral on TikTok and Reels
Step 1: Lead with a feeling, not a synopsis. No one stopped scrolling for Dungeon Crawler Carl because a video explained the plot. They stopped because something hit in the first three seconds: funny, shocking, “wait, what.” If your opening line is a summary, you’ve already lost the viewer. Explain later, if at all.
Step 2: Give people something to claim as their own. You can’t manufacture a “Luminary” or a #BatBoys directly. What you can do is leave gaps for fans to fill in: an undefined dynamic between two characters, a name that begs for a nickname, a moment built for a sound. Then step back and let people build on it. Once it’s their inside joke instead of your marketing copy, it spreads without you.
Step 3: Sell the characters, not the plot. “POV: you’re the only one who survived the trial” outperforms “Book Two follows Carl as he descends further into the dungeon” almost every time. Audiences connect with characters first. Plot is just the reason they keep watching.
Step 4: Show up consistently, in the right room. Romantasy BookTok, LitRPG BookTok, and thriller BookTok are different audiences with different formats, sounds, and running jokes. Figure out which sub-niche your product actually belongs to and post there several times a week, not once a month. Trying to appeal to everyone usually means reaching no one.
Step 5: Once it catches, let others carry it. Both of these titles built momentum through reader-generated content before any real ad spend followed. Once you have organic traction, put budget behind what’s already working (creator partnerships, boosted posts on existing viral content) instead of starting a separate campaign from zero.
A quick aside on why this works everywhere
BookTok gets attention because it’s about books, but the mechanism behind it has nothing to do with books specifically. Every audience online has already carved out its own corner, with its own aesthetic and its own shorthand. WitchTok. FitTok. CottageCore. DarkAcademia. MomTok. Whatever your product or industry is, there’s already a “-Tok” for it, fully formed, waiting for someone to speak its language instead of dropping a generic ad into it.
BookTok is just the easiest example to point to because the results are public: ten million books sold, a cat with a Peacock deal, a theme song nobody officially commissioned. Fantasy novels, supplements, industrial equipment, whatever you’re selling, the mechanism holds. Find your audience’s “-Tok,” learn what it already values, and give it something worth building on.
Hot faeries and a talking cat just made that easier to see.
Want help finding the “-Tok” (or platform equivalent) where your audience already lives?
That’s a massive part of what we do at Big Red Jelly.
Frequently Asked Questions About Book Marketing & Virality
What is BookTok, and why does it matter for book marketing?
BookTok is the reading community on TikTok, currently responsible for over 370 billion views and tens of millions of book sales a year. It matters because it proved something bigger than books: word-of-mouth inside a tight-knit niche audience can outperform paid advertising, given enough time.
Why did Dungeon Crawler Carl explode in 2026 after being out since 2020?
The series built quietly for four years through self-publishing, Audible, and word of mouth. In 2025 and 2026, that momentum surfaced publicly: a Books-A-Million Book of the Year award, a Peacock TV greenlight, and a tabletop game that raised $13.3 million in crowdfunding. It was not just one title breaking out, but the broader Dungeon Crawler Carl series expanding across formats and merchandise. That expansion now includes a tabletop rpg and print edition bonus content. The explosion was six years in the making.
What made ACOTAR go viral on TikTok?
Fans built an entire world on top of the books that Sarah J. Maas never had to create herself, including a fan-made theme song called “Luminary” and the #BatBoys trend around three of the series’ male leads. That fan-generated content did more marketing than an official campaign could.
Does the "find your niche's -Tok" strategy work outside of book marketing?
Yes. BookTok is just the most visible example of a pattern that repeats across TikTok: WitchTok, FitTok, CottageCore, DarkAcademia, and more. Any product or industry has an existing niche community with its own language and values. Find it, speak it, and let fans build on it.
How often should I post on TikTok or Reels to build momentum?
Consistency matters more than perfection. Aim for several posts a week in your specific sub-niche rather than one polished video a month. Both Dungeon Crawler Carl and ACOTAR built momentum through frequent, authentic content, not occasional high-production posts.
Do I need a big ad budget to make a book go viral?
No. Both case studies in this post started with zero ad spend and grew through organic fan content first. Paid promotion, like creator partnerships or boosted posts, works best after organic traction proves the content resonates, not as the first move.
