What is more exciting about the internet than books? Well, I'll bet the three things most people do online are watch videos, play games, and read. Videos and games are very old passtimes, and their appearance on the net is no surprise. It's just television and arcades in a new package. Then there's reading. People claim not to like reading, but then they spend a lot of time online reading emails, Facebook updates, Twitter and short-attention-span articles the size of sound bites. What is different about that form of reading as opposed to reading books? For some of it, there's the social factor - it came from my friends, so it has higher value to me. But most of it, I suspect, is the attention span issue. Too long, didn't read. What you're saying when you won't read long articles is that you are too distracted.
Mokalus of Borg
PS - Personally, I'm a fan of both.
PPS - And I'm moving towards ebooks as my primary reading material.