In terms of sales, Harry Potter remains the most successful novel in history, with over 500 million copies sold since it was first published in 1997. So what did Rowling do differently? How does Harry Potter distinguish itself from other young-adult and fantasy series? What is it about that cowlicked, bespectacled young man that keeps hundreds of millions of twenty- to thirty-somethings clinging to a piece of their childhood? The blockbuster movies certainly helped, as did the all-hands-on-deck marketing campaigns and the digital tomes of apocryphal material, fan fiction, and interactive content. But this short essay focuses solely on the content, on one facet of the books that keep fans coming back: self insertability.
Unlike some of its contemporaries like A Series of Unfortunate Events and The Spiderwick Chronicles, and even earlier series that draw comparisons such as Lord of the Rings and Chronicles of Narnia, the Harry Potter series focuses on a sole, titular protagonist. All of these other series lean more towards an ensemble of characters. So, rather than insert themselves into the narrative as a totally new character, a fantastical version of their real selves, readers are more tempted to project themselves onto an existing character. Take the online personality quizzes as evidence. With a series like Lord of the Rings, the question will inevitably be "Which Lord of the Rings Character are you?" Compare that to the interactive Potter content, which focuses on building a wizarding alter ego for the reader. The question isn't Which character are you? but rather Which house would you be sorted into? and What is your Patronus? and What would your wand be made of? These questions aim to incorporate readers into the world of the novels as themselves.
Rowling laid the infrastructure for this self-insertable world by writing numerous opportunities for sorting and customization. When Hogwarts students matriculate, the first order of business is being sorted into a house. Each house has a reputation, and the house a person is sorted into reflects on their personality. Gryffindors, for example, are considered to be courageous and noble. Hufflepuffs are regarded as friendly and laid-back, while Ravenclaws are seen as intellectual, introverted, and focused on their studies. Slytherin's are "edgy," verging on evil. Every wizard has a unique wand, every wizard has a unique Patronus and preference of magical creature, and every wizard has magic at their fingertips. In all of these categories, readers see opportunities to define themselves. The tendency to sort oneself as existing characters isn't as strong with the Harry Potter books because Harry is the titular character, and the novel all but revolves around him. But the people he meets along the way could just as easily resemble any reader.
