The seventh and final book in J.K.Rowling's Harry Potter series has become Amazon.com's most popular pre-ordered product.
The Internet retailer claims customers have ordered nearly 1.6 million copies ahead of the book's release on July 21. Amazon said on July 2 that Harry Potter and the Deathly Hallows surpassed the previous record of 1.5 million orders set by its predecessor, Harry Potter and the Half- Blood Prince.
The retailer predicted that orders would continue to rise by "many more hundreds of thousands of copies."
The six published Harry Potter books have sold around 325 million copies worldwide, and Rowling is known as the first-ever dollar-billionaire author. The books have also spawned a successful film franchise, with the first four installments earning global ticket sales of around $3.5 billion.
The fifth, Harry Potter and the Order of the Phoenix, releases later in July. The final movie is due in 2010. Harry Potter is published by Bloomsbury in Britain, while Scholastic Corp. distributes the novels in the United States.