Since the 30 June 1997 release of the first novel
Harry Potter and the Philosopher's Stone, the books have gained immense popularity, critical acclaim and commercial success worldwide.
[2] The series has also had some share of criticism, including concern for the increasingly dark tone. As of June 2011, the book series has sold about 450 million copies and has been
translated into 67 languages,
[3][4] and the last four books consecutively set records as the fastest-selling books in history.
The initial major publishers of the books were
Bloomsbury in the United Kingdom and
Scholastic Press in the United States; the books have since been published by many publishers worldwide. In October 2011, the series will be released in various ebook formats through "
Pottermore".
[11] The books have been made into an eight-part
film series by
Warner Bros. Pictures, with the seventh book split into two parts; it is the
highest grossing film series of all time. The series also originated much
tie-in merchandise, making the
Harry Potter brand worth in excess of $15 billion