Fastest-selling book of fiction in 24 hours

The fastest selling book is Harry Potter and the Deathly Hallows, the seventh - and final - novel in JK Rowling's (UK) Harry Potter series, which sold 8.3 million copies in the first 24 hours (or 345,833 books per hour), following its release in the USA at 00.01 on 21 July 2007. The novels follow Harry's life at Hogwarts School of Witchcraft and Wizardry.

UK retailer, WHSmith claimed that 15 books were being sold per second!