On December 17, 2014 The Verge.com issued "The Everything Book: Reading in the Age of Amazon" by Casey Newton. This excellent article discussed Amazon.com's product development in e-readers and audible books.
Among the take-away ideas from the article that particularly caught my attention, it is likely that at its Lab126 in Sunnyvale, CA, Amazon has spent more time studying the physical act of reading than any company before it:
" 'When you're reading, you want to fall down the rabbit hole' . . . Amazon has actually built a rabbit hole, of sorts: a reading room somewhere at Lab126, stuffed with comfortable chairs, where pinhole cameras study the way people really read. (Because test subjects are in there using prototype devices, I am not allowed inside.)
"It’s in this room that Amazon learned people switch hands on a book roughly every two minutes, even though in surveys they claimed not to. (This is why the Voyage has identical page-turn buttons on both left and right.) The Voyage’s page-forward button is much bigger than page-back, because Amazon’s data showed 80 percent of all page flips are forward. As Green describes research like this, it seems likely that Amazon has spent more time studying the physical act of reading than any company before it.
Amazon's Audible division, headquartered in Newark, NJ, had a catalogue of more than 180,000 audiobooks in December 2014, with countless more in rapid development. In 2012 Amazon introduced a feature that let you switch back forth easily between the written and audio versions of a book. In December 2014 there were 55,000 books which could be read on an Amazon Kindle in this way.