Picked this up as I read Richard's blog, which is witty and interesting.
I have played a couple of MMOs in the past but am not a professional games designer or anything like that. I recommend that you pick it up if you are at all interested in games and how they are made. It is broken up into a series of short, discrete articles which weave together to form an overarching narrative - in a clever and, I am sure, deliberate way it is like an MMO itself. This episodic nature makes it perfect to dip in and out of for a few minutes at a time and read over an extended period (I think it has taken me over a year).
I cannot recommend it highly enough, I have really, really enjoyed it and will be getting hold of some of Richard's other books and fiction to try those too.