This quote is worth reading from the ever-terrific StackExchange blog:
I’ve come to realize that the conservative school of community moderation is the right school of community moderation, at least for Stack Exchange.
When Joel & Jeff first sat around the campfire and dreamed up Stack Overflow, they did so with an insight in mind: They weren’t going to just create a forum where a user can receive an answer. SO (and later, SE) would be a platform to encourage intelligent, invested answers deserving of links across the Internet and useful for generations to come.
Too local? Take it to Yelp. Too easy? Take it to Google. Too subjective? Take it to Quora. Too fun? Take it to Facebook.
Stack Exchange is about objectively correct answers that stand the test of time. There is little room here for questions that ask for something less correct or less permanent.
The brilliance here is Joel Spolsky was able to pinpoint precisely where the StackExchange community fits amongst the existing ecosystem.
You can’t do this from the outside. You can’t identify the unique positioning point unless you are deeply embedded within the ecosystem already. Don’t overlook where your community is positioned within the ecosystem, it makes a big difference to the success of your community.