Before I get back to the book review
here's an interesting article from the latest "Clarksworld":

"Of Dice and Men: Modern Fantasists and the Influence of Role-Playing Games"

My perspective, for what's it's worth: my brain cooks better when it's warmed by GMing or playing in a good game, but there's also a definite bent toward wanting to write your own gaming fanfic instead of Something Original. I'm weak on plotting (and probably other things, too, but let's stick with that one) and sometimes when I can't figure out what happens next, I need to mentally throw the plot to the gamers in my head to let them figure out what really does happen next.