I buy physical books for every book I read, other than humble bundles (typically for programming e-book bundles). I put a lot of my income toward books though, which is maybe not advisable, but I simply love having a ton of books in my home

I typically buy used books on ebay when I want something specific (often technical books), but for fiction I often browse one of the used bookstores around me, or grab a random book from one of those little library book-boxes-on-a-stick. I like to follow the whimsical approach of reading books that come to me