Why should a QnA site need a community wiki ?
This is a general question- I want to hear your opinions. What type of forums and communities need a wiki feature enabled?
Followup question - Why should one have a wiki alongside QnA forum?
EDIT: I meant a community wiki.
Possible duplicate of http://askbot.org/en/question/6643/what-is-the-intention-of-community-wiki-questions/