This didn’t turn out the way I expected. When I was searching for a comparison of an audience share of these type of users of Kindle formats versus Nook readers, naturally the term “reader” did not mean the noun of a person to the search engine in the machine. An interesting site popped up about comparing Kindle tablets to Nook tablets and Kobo. Not exactly what I was looking for but I learned about the virtual ink process or design called “E Ink Display” that allowed for daylight reading and how that works. The site has more product information and comparison at:
Also, along this vein ………
https://www.cnet.com/news/kindle-vs-nook-vs-ipad-which-e-book-reader-should-you-buy/
And: ………. https://pickmyreader.com/kindle-paperwhite-vs-nook-glowlight/
Getting back to the main question is there a trend in the users between these three types of e-book readers as an audience?
The answer I found is a year old, October 2015, but is comprehensive in its scope and detail. I could recreate the data and graphs, but why? I’ll just send you to the site which is ……. A must lesson for any author, and, well, any striving writing.
I feel fortunate that my publisher provides most of these platforms. That site is HUGE and at:
What do you think?
Tim
Timothy J. Desmond
Amazon author page at: http://www.amazon.com/-/e/B00694KQQO
Books and Writing at: http://timothydesmond.wordpress.com
Art at: http://artbydesmond.wordpress.com
timdesmondblog 
Good grief, Timmer. You look like Ernest H’s twin freaking brother!!!!!
Tell you what, Richard. That shot of me is in Key West at the place called Captain Tony’s. It was the original location of Sloppy Joe’s that moved a half a block down the same street. Behind me on the wall with all the business cards, is a photo of Captain Tony. He was Hemingway’s boat captain on the Pilar from Cuba. I was raising toast to both of them.