Jeff Vogel - Three Reasons Creators Should Never Read Their Forums. Thanks Ant via Slashdot.
When I read the forums for, say, World of Warcraft or xkcd, I'm always amazed at how nasty things get. It makes me think, "If you hate it so much, why are you there?" But that's just the way it is, and excess exposure to insults can really get under your skin, make you doubt yourself, and interfere with your work. It's very sad, but you sometimes need to just protect yourself by staying away. Keep your brain clean.

Cliffski’s Blog - But forums are great (bring a dagger).
The big danger, and Jeff mentioned this, is that you can’t get too swayed by the forum posters into switching design decisions. There is a big temptation to do this, but be wary. If I look at the percentage of GSB buyers who are forum posters, it’s pretty small. They are a tiny percentage of the playerbase, and not the group that I should really take design cues from. Some of their ideas are truly cool (someone mentioned fighters that could repair other fighters recently), but the key is to knowing when you have spotted an idea that really is good, and when you are following the crowd.