Interesting fact:

Eight publishers rejected Harry Potter but after it was finally picked up for publication, J.K Rowling only received £2500 as an advance. The seventh and final novel, Harry Potter and the Deathly Hallows, was published on 21 July 2007. The book sold 11 million copies in the first 24 hours of release, breaking down to 2.7 million copies in the UK and 8.3 million in the US.