Eventually I filled up several bookshelves with my technical library. When I picked up a first generation iPad I decided it was time to go all digital. I had experimented with Safari online, but it was never a replacement for my library. I went cold turkey with buying paper books. At this point I was mostly purchasing a lot of pragprog titles and transferring them to iBooks. And beta books don’t ship in paper.
A few weeks ago I realized I had moved to a subscription model. Now I just download my books from pragprog when I need them. No need to keep a bunch of titles in my library when I can pull down the up to date versions. I can also read them on my laptop, iPad, or iPhone anytime I want with a nice retina screen.