I have thousands of books, all free and I would not be able to walk through our small house if they were all in my space instead of digital space. Secondly, I think I have dyslexia - at any rate I read on ereaders but never touch real books unless forced to. I could read on pc/laptop but ereaders are much easier.
I have a kindle with 1400+ books on it as of date, most all free. I have collected other digital books from the net and have in the 20,000 area at present on my desktop.
My wife likes this type of collecting much better than old cars :-)