I just took it. Very good survey.
One thing I can't quite pinpoint is, apart from the convenience, light, accessibility, etc. There is something else that makes it harder and harder for me to pick up a paper book. I have a tower of 20 TBR paper books that I just keep avoiding, because I can't be bothered with them. Some of them are from the library, because I could not find them on Overdrive, yet I keep starting new books on my kindle.
I think there is some emotional component to it as well, in my case. The more I read on my kindle, the less I want to pick up a paper book.