From Common Craft- Social Design for the Web:
"Blogs and message boards both suffer from the same problem- they are great for presenting emerging information, but poor at organizing it for future reference. The “good stuff” that people often need and companies often want to capture quickly gets buried among all the comments and messages.
You could say that blogs and message boards are good at managing flows, but poor at managing stocks.
With this post, I’m outlining a potential way organizations can use blogs and message boards as a way to generate useful information and a wiki as a way to filter, archive and organize it for future reference."
Read more here.