Paperback
Most of the reviews on Goodreads start with something like, "I didn't actually read the book, I read it online..." which is fine for the content of the very inventive/clever/funny comic itself, but to not have read the author's book-only comments about what he was thinking, what his intent was, and just random laugh-out-loud current observations is to have really missed out. The book may be a true representation of the online experience, but it's an experience with its own worthwhile extras.
I did "cheat" a little and check out the online pages after reading it so that I could see any flash stuff that couldn't be rendered in the hard copy, but even if I had no internet, the book would stand just fine on its own. I don't know what lies ahead in the thousands of online pages, but the beginning here is more than promising.
B+