IT TRANSFORMED a struggling teacher into one of Britain's most wealthy women and created a multimillion-pound publishing phenomenon.
But apart from making JK Rowling Scotland's richest woman, the teenage wizard she created has also persuaded millions of children to spend less time on computer games and televisions and more time with books.
New research by the Federation of Children's Book Groups (FCBG), shows that JK Rowling's storytelling has had a major impact on literacy and reading habits in the UK.
Almost six out of 10 children (59%) think the books have helped them improve their reading skills. And 48% say Rowling's creation is the reason they read more.
Teachers are even clearer about the effect Rowling's series of books, the sixth of which will be released this week, have had on reading: 84% say Harry Potter has helped improve child literacy and 67% claimed the series has turned non-readers into readers.
Colin Harrison, professor of literacy studies at the University of Nottingham, who contributed to the research, said: "The sheer pervasiveness of JK Rowling's books means Harry Potter will certainly have impacted on children's literacy levels.
"Reading and re-reading books is very valuable in building fluency, and there is a strong link between reading books for pleasure and improvement in word recognition and comprehension."
Reading a Harry Potter book stretches a child's ability. More than half (51%) of the 1,000 children surveyed thought the books were tough to read but worth sticking with.
Teachers also think Rowling's clever writing and plot development are a challenge to youngsters, with 73% claiming to be surprised that children manage to read the books at all. However, 61% of those surveyed by the FCBG, an independent voluntary organisation, say Rowling's books are so good that the length of them does not matter.
Alison Lewis, who teaches English to pupils aged 11 to 17 at the Wester Hailes Education Centre in Edinburgh, said: "There has been a lot of excitement in the last few weeks of term about the new Harry Potter book. They are fascinated by what is going to happen next. The characters in the books appeal to girls while the boys seem more interested in the storyline. The most important thing is that it gets them interested in reading."
Other key findings in the survey included:
41% said the Harry Potter books have made reading cool;
39% said they would miss their favourite television programme to read the new book;
66% said most of their friends have read Harry Potter;
70% of teachers say that Harry Potter books are talked about in the playground.
George Grey, head of children's books at Waterstone's the booksellers, said: "When children find books that inspire them, their enthusiasm leads them to read more."
The first five Potter books have sold more than 265m copies in 200 countries and have been translated into 62 languages, according to figures compiled by Nielsen Bookscan. Audio versions on CD and tape have sold over 1.1 million copies - making them the bestselling audio books ever.
Retailers are gearing up for a final push before Saturday's launch of Harry Potter and the Half-Blood Prince.
WH Smith claims one in four copies of the new book will be sold in its 390 branches across the UK. A spokesman said: "We expect it to be our biggest ever pre-ordered product, beating the 300,000 figure for the last book. We are taking thousands of orders each day."
Amazon, the online book retailer, has taken pre-orders of Harry Potter and the Half-Blood Prince from 150 countries, and has also experienced a 17% rise in pre-orders of the adult version of the book.
Rowling will read the new book in the Great Hall of Edinburgh Castle on Saturday. The reading will be beamed by satellite to television and radio stations around the world.
Richard Perks, a research analyst with the Mintel retail consultancy, said: "The Harry Potter phenomenon is growing because the books do not suffer sequel syndrome. Each book is original. They don't bleed more out of the same formula."
Waterstone's predicts Harry Potter and the Half-Blood Prince will sell more than two million copies in the UK on its first day, the fastest sales yet.