BookTok influences what you read, even if you aren't on social media

Romance novel The Hating Game was published 10 years ago, before online bookish communities were as massive as they are now. 

Back then, Sally Thorne's debut novel became popular through word of mouth. 

But things have changed.

"The word of mouth that originally sold my book is now social media recommendations, which seem to hold just as much weight," the Canberra-based author says.

If you're looking for a new book to read, you may ask family or friends for a recommendation, but it's increasingly likely that you use social media.

According to the Understanding Australia Reads survey, about 80 per cent of Australians read a book at least once a year; of those readers, 8 per cent searched for books through book-related social media.

Of the book-based online communities, BookTok is by far the biggest. 

It's a hashtag on TikTok that now has more than 85 million videos contributed by an international community. 

But many of the biggest creators and books featured in videos are from the US and the United Kingdom.

"I would say of my book sales, 1 per cent would be Australia and 90 to 95 per cent would be the US and the rest would be the UK," Thorne says.

BookTok is only the latest addition to online book sub-communities, with the original platforms Bookstagram (Instagram) and BookTube (YouTube) dating back more than 10 years.

These social videos are often spoken about as a form of word of mouth, but is that really the case?

Marc Cheong, a senior lecturer at the University of Melbourne, says they're unlike other recommendation methods.

When you have a book recommendation from a friend or book club that you may not have liked, you aren't bombarded with recommendations for similar titles.

"There's no central intermediary that says, 'Hang on a second, you might like to read this one,'" Dr Cheong says.

Algorithms craft what we see

According to Dr Cheong, the word "algorithm" has become shorthand for how social media companies use our data to craft the feeds we see. 

To understand what TikTok's algorithm does when serving up book content, Dr Cheong suggests thinking about the interests of social media platforms.

He points to advertiser revenue, with the goal of keeping users engaged to view as many ads as possible.

The data they use to make your social media feed comes from the videos you like and comment on, your demographic data, and even the data of people similar to you, all to keep you scrolling. 

Eleanor Spencer-Regan, an honorary senior fellow at the University of Melbourne, says TikTok's core audience is young women, teenage girls, LGBTQIA+ and culturally diverse communities. 

"It feels like a safe space on the internet for [them]," Dr Spencer-Regan says.

This helps to partially explain why many videos on BookTok feature romance, romantasy (romance fantasy), and crime genres. 

Tropes make themes popular

In many romantasy books, there is an element of categorising books for what readers may like through tropes like an enemies-to-lovers arc or a one-bed scenario plot.

Tropes have been used in book marketing for a long time, way before social media.

"And that [trope] in itself was almost like a hashtag," Thorne says.

Alongside #BookTok, creators will use hashtags like #slowburn or #rightpersonwrongtime to help users and the TikTok algorithm find books they may like. 

It helps recommend tropes and amplify books with similar plots.

But this function can also make too many similar books popular.

Dr Cheong says genre similarity has become a definite by-product of TikTok's algorithm.

"Imagine in mathematical terms, it would just regress to the mean, the average, or what's most likely to be common," Dr Cheong says.

"So we can see this effect on the content being pushed on social network feeds," he says.

This isn't limited to online communities: the virality of videos shows up in the books approved for publishing and in social trends. 

Real-world impacts

One of the biggest examples of a BookTok bestseller is the first title of the Empyrean series, Fourth Wing, by Rebecca Yarros.

It's a romantasy series featuring a military school of dragons, magic, and high-stakes plots for a group of 18-year-olds. 

Before Fourth Wing hit shelves in the United States in 2023, it was approved for an initial hardcover print run of 315,000 copies, Dr Spencer-Regan says. 

"To put that in context, for a trade hardback … anything over 75,000 is usually considered a very large print run," she says.

Even Thorne says recent sold-out games for her local ice hockey team can be attributed in part to BookTok.

"If anyone goes down to the local hockey arena and wonders why there are so many young women at the boy aquarium, then that is because [ice] hockey romance is really hard [online right now]," Thorne says.

This interplay between real life and the virality of online videos contributes to the perception of how popular a genre like romance is.

"It kind of co-creates the overall perception of how a book is doing," Dr Cheong says.

Over the past decade, Thorne says she's seen a shift in readers' expectations and the frequency authors are expected to publish, but she says online spaces are valuable for the bookish community.

"An indie author can write a book, upload it, and be selling in the middle of the craze," she says.

"It's awesome to see."

Even though ice-hockey romance is quite popular right now, Thorne says she doesn't have plans to write one anytime soon.

Despite bucking the latest trend, she still benefits.

"Thanks to BookTok and new readers finding this hobby, my book has continued to sell for 10 years instead of just fizzling out."