[buddapalm]

observe the free falling sales of ereaders in more recent years (any public market research will do), and you'd understand that Amazons ebooks business needs these old devices more and more.

[mrob]

With phones getting bigger there's less need for dedicated ereaders. I mostly read on my phone, and I know other people who do too. The convenience of having books in your pocket outweighs the small screen size. From a 2015 article on phone reading ( http://www.wsj.com/articles/the-rise-of-phone-reading-143939... ):

"The number of people who read [e-books] primarily on phones has risen to 14% in the first quarter of 2015 from 9% in 2012."

I can't find more recent statistics but I expect it's continuing to rise. Convenience always beats quality, eg. MP3 vs CDs, early LCDs vs CRTs.

[Retric]

Heavy users may be more likely to use dedicated readers so % of total users is less important than % of book sales.