Dan Brown's Inferno posted a massive debut, selling 369,000 copies at outlets that report to Nielsen BookScan. The number was more than enough to make it the #1 bestselling book: the #2 title, Happy, Happy Happy by Phil Robertson, sold 43,000 copies for the week. In fact, Inferno racked up more than half of the sales for the entire top 50 frontlist hardcover fiction for the week. Translation: more than one in two hardcover fiction books sold was Inferno, and the book looks well on its way to being one of 2013's bestselling books.

Doubleday reported that Inferno sold 1 million units (print + e-book) in the U.S. and Canada in its first five days. Because BookScan's figure of 369,000 tracks somewhere around 80% of print sales, the total number of print units sold should be somewhere around 500,000 copies total, meaning that the e-book version accounted for about half of Inferno's totals.

And though Inferno's debut tops recent blockbusters like The Casual Vacancy (157,000), No Easy Day (254,000), and the most recent Wimpy Kid title The Third Wheel (362,000), Dan Brown's latest debuted far below the debut of his previous novel, The Lost Symbol, which sold 1,163,000 copies in its first week. In 2009, when The Lost Symbol was published, e-books were a much smaller source of sales for publishers, but even excluding e-books from Symbol's 1.1 million debut yields a higher total than Inferno's 1 million p + e total, as reported by Doubleday.

This time last year, Fifty Shades of Grey was Nielsen's #1 bestseller with 375,000 copies sold.