The main advantage of a wiki is that all people can easily edit the documents stored in the wiki. And a wiki usually has a revision control which is also very useful for maintaining all kinds of documents. This makes it very valuable as a knowledge base.
I made some good experiences with a wiki system, even if some bad guy deleted all content it can easily retrieved because of the revision control
.
Therefore it might also be useful to give everyone access to at least a part of the wiki, not only the stuff members. E.g. I for myself am not a stuff member but feel that I can contribute much to this community due to my employment and years of experience at this hole matter. In the last days saw a lot of questions which all covered the same topics. Those could go to the wiki and would save a lot of time (well maybe not, some people are very resistant to reading
).
Or another suggestion:
Make use of the FAQ at this website. It's already there but without content it's useless...