is calling this one of its best Christmas shopping seasons ever after more than 1 million consumers signed up for Amazon Prime, the online retailer’s free unlimited 2-day shipping deal, the week before Christmas. The online retailer said it was record year for Amazon Prime subscriptions, mobile shopping and sales of Amazon e-readers as Amazon also highlighted a big increase in content offered via its e-book lending program, Kindle store and Amazon App store.

According to information released by Amazon, its Prime all-you-can-ship-for-free-program now has “tens of millions” of subscribers after more than a million new users signed up the third week of December. In addition, Amazon noted that more than half of its customers this shopping season used a mobile device; and that the Kindle Lending Library grew from about 250,000 books to more than 475,000 books available for lending. Amazon also added more than 200,000 “exclusive” e-books to the Kindle store in 2013 and there are more than 100,000 apps in the Amazon App Store (double the number available last year) for Kindle Fire tablet devices. All told, Amazon said, there are more than 27 million content items available for sale via, including books, music, films, audiobooks, games, TV shows, books, magazines and apps.

Amazon also pointed out that 150 Kindle Direct Publishing authors each sold more than 100,000 copies of their e-books in 2013. Overall KDP authors sold “hundreds of thousands” of e-books during the month of the November.

Among the bestselling holiday books on are Jeff Kinney’s Diary of a Wimpy Kid: Hardluck, Charles Krauthammer’s Things That matter: Three Decades of Passions, Pastimes and Politics and Rush Limbaugh’s Rush Revere and the Brave Pilgrims: Time-Travel Adventures with Exceptional Americans. The bestselling Kindle Books are John Grisham’s Sycamore Row, Donna Tartt’s The Goldfinch and Rush Limbaugh’s Rush Revere and the Brave Pilgrims.

There was such demand for items sold online that many gifts failed to make it to customers by Christmas. Though UPS and Fed Ex took most of the blame, Amazon was offering gift cards to come customers whose gifts did not make it to their homes by Christmas.