Amazon today revealed that it now ships more items with the free two-day shipping method included in an Amazon Prime membership than with the free "Super Saver" option available to non-Prime customers. Benefits of the $79 subscription have grown in recent years, with an Instant Video streaming library that now exceeds 22,000 titles and exclusive access to the Kindle Lending Library. So while Amazon's "major milestone" illustrates the massive success of Prime, we don't find it all that shocking. However, the company also took the opportunity to highlight the most popular items (both physical and digital) available via Prime, and you may be surprised by some of the data.

So far in 2012, for instance, E. L. James' Fifty Shades of Gray: Book One has been the fourth best-selling item through Prime, trailing only Amazon's line of Kindle hardware in overall popularity. On the digital front, Instant Video viewers have taken a liking to the Crawley family; season one of Downton Abbey ranks first among TV shows. For movies, the original Swedish version of The Girl With the Dragon Tattoo (with subtitles, naturally) takes the top spot. Easily the biggest upset, though, is the most popular book in the Kindle Owners' Lending Library: The Hunger Games managed to beat out J.K. Rowling's Harry Potter series. For other tidbits of Prime data, hit the source below for Amazon's full PR blast.