Book sales had a strong showing in the week leading up to Christmas with sales rising 24% over the prior week at outlets that report to Nielsen BookScan. The 27.3 million print units sold during the week ended December 23, moreover, was a 5% increase over the last week before Christmas in 2011 when 26.1 million units were sold.

Gains were driven by the children’ categories with nonfiction up 19% and fiction ahead 7%. The adult categories had more modest gains with fiction sales increasing 2% and nonfiction up 1%.

Sales through retail and clubs rose 6% in the most recent week over 2011, while sales through mass merchandisers and other retails were 3% down compared to last year. Frontlist and backlist titles performed about the same with frontlist up 5% in the week and backlist units ahead 4%. Sales in BookScan’s South Atlantic region had the biggest gain in the week with sales up 12%, while sales were weakest in the Middle Atlantic where they were flat with 2011.

Jeff Kinney’s The Third Wheel was the top selling title in Christmas week at outlets that report to BookScan, though its 186,214 units sold was actually 4% behind the sales volume in the previous week. Bill O’Reilly took second and third place in the week with Killing Kennedy and Killing Lincoln. The Racketeer and Proof of Heaven rounded out the top five bestsellers. And how did the book of the year do as a Christmas present? Fifty Shades of Grey landed in ninth place in Christmas week, selling a shade under 65,000 units.