Both. I much prefer physical copies, but for a lot of the stuff I read those are kind of hard to find. A lot of the horror stuff I like in particular is nigh-impossible find because most stores seem to only have Stephen King, Joe Hill Anne Rice and Dean Koontz stuff available (not that those authors are bad except for Dean Koontz, who is so formulaic and unimaginative I can't help but imagine a flowchart when reading his stuff). Which is an absolute travesty given how good authors like Brian Keene, David Keene and Johnathan Maberry are. When it comes to manga a lot of the stuff I like is rather obscure seinen, which means unless an anime adaptation is in the works it's hard to find. Comics I have a bit more luck with, but trying to find certain things is nigh-futile. I can't recall seeing a single 2000 AD collection for example, or a graphic novel volume of NoTLD: Aftermath or The Extinction Parade in a very long time. So I often use ereaders to fill the gaps.