As of 2008, more than 400,000,000 (400 million) books in the Harry Potter series have been sold.

The books have been translated into more than 67 different languages around the world.

As an example of how popular the Harry Potter books are, the final book in the series, Harry Potter and the Deathly Hallows, sold 11,000,000 (11 million) copies in the first 24 hours of its release.  That would be almost 500,000 books sold each hour.