It's the label that every author dreams of having on the front of their book: "Sunday Times Bestseller".
The newspaper produces weekly sales charts for hardback and softback book sales in the UK.
And they recently announced which books sold the most in 2023.
Here are the top 11 children's and young adult bools. You can see the full list here.
1. A Good Girl's Guide To Murder by Holly Jackson
The winner of the British Book Awards' Childrens Book of the Year Award in 2020 (although it's perhaps unsuitable for younger teenagers) tops the bestseller list in 2023, shifting 170,481 paperbacks. "Five years ago, schoolgirl Andie Bell was murdered by Sal Singh. The police know he did it. Everyone in town knows he did it. But having grown up in the same small town that was consumed by the crime, Pippa Fitz-Amobi isn't so sure. When she chooses the case as the topic for her final project, she starts to uncover secrets that someone in town desperately wants to stay hidden. And if the real killer is still out there, how far will they go to keep Pip from the truth…?" | Contributed
2. Robodog by David Walliams and Adam Stower
Comedian and television star David Walliams takes the silver medal with his latest book illustrated by Adam Stower, which has sold 156,205 hardbacks in 2023. "Bedlam is one of the most dangerous places on Earth – home to a host of wicked villains. Nothing and nobody is safe from these evil criminals. The city needs its own superhero to defeat the supervillains. But who? Robodog!" | Contributed
3. You Choose Your Adventure by Pippa Goodhart & Nick Sharratt
This instalment of the 'You Choose' series was released as part of World Book Day and sold 143,375 paperbacks. "Welcome to your adventure! What will you wear? Where will you go? Who would you like to meet on the way? Discover a different story every time with this magical storytelling toolkit - let your imagination run wild!" | Contributed
4. Marvel Spider-Man Pocket Guide by Catherine Saunders
Another World Book Day title takes fourth spot. The guide to everything in the SPider-verse sold 136,833 paperbacks. "Discover everything you ever needed to know about Spider-Man and the Spider-Verse! Is Spider-Man speedier than Spider-Ham? Who has more fighting skill, Venom or Vulture? Pick up this Pocket Guide and you'll have all of these Spidey facts and more at your fingertips." | Contributed