I eventually read all books I purchase. Does it take me a while sometimes? Yes. I still have kindle books purchased going back to 2008. The largest chunks were purchased in 2011 and 2013 for some reason.
I'll get to them. They are there waiting for me. Although I don't really read a lot of best sellers. I do read a lot of romance and looking at the site, we romance readers seem to be on the top of the list of those reading the books they buy.
Anyway, I hated Gone Girl and gave up about 35-40% in on it. Its rare for me not to finish books so that tells you how much I disliked it.
I have a vetting system I use but occasionally I veer of it. Doesn't end well usually.
I have many books still unread I purchased because I buy on sale. I know the authors and publishers so I buy when the price drops. I have always had a lot more books around me than I have read, its just much easier now to do so with ebooks. No space issues.
And they can track me easy at Amazon if they want to. Although I back up my books in Calibre, I read the ones from the Amazon cloud and always sync up regularly.