I do both. Not a huge process of deciding really. I mostly borrow ebooks from the library to read on my Kindle but I do check out physical books too, depending on what is convenient and/or available. I also buy books regularly. We have a decent sized library (we both worked for B&N in the past, I worked in a used book warehouse, he's now a librarian) Guess it depends on if I'm fairly certain I'll want to own it eventually (authors I'm familiar with, classics, etc) or if it's an impulse read (I've read a lot of the "Duke Classics" epub ebooks from the library lately, but I'd like to buy them eventually because I loved them) Many books I wanted to read this last year the library didn't have. In a couple cases I requested them, and they got them for me. In a couple cases I just jumped on Alibris and bought the book. I follow r/ebookdeals and buy those sometimes. There's a great used bookstore here in town I keep meaning to get to and go browse and see what I can turn up. I have a lot of comics on my pull list, which I read ongoing rather than wait for the collected edition/graphic novel, but sometimes I read those through Marvel Unlimited or Hoopla or something digitally too. So I do a little bit of everything. I just like to read a whole lot! I don't have a specific process for deciding how, I just end up doing it.