Sure but consider Kindle ebooks, for example. Finding a pirated copy of a book, dealing with the hassles of torrenting or some kind of download site, manually loading the book over, risking all kinds of phishing scams or viruses on the sites that serve this stuff - this is all way too much hassle. I'm happy to pay the $10 for the book even though I know I don't have to.
Making money selling digital goods is all about making paying easier than stealing.
I don't believe that DRM deserves the credit because I have yet to observe any such deterrent effect, while conversely, I have heard of many who turned to piracy due to feeling cheated by DRM.
I'm just curious, but have you ever observed anyone give up and buy something because they failed to pirate it?
Making money selling digital goods is all about making paying easier than stealing.