One more thing....

I don't know how much tagging matters, I think it's useful if you're searching for something specific. I nearly always tag the discussions I respond to, unless I really can't think of anything relevant to add. If I'm starting a discussion, I always put tags on it, for me though, they're usually just the keywords of whatever I'm talking about in that post.

I am not sure that the tagging matters much. I almost never do it. It is just an annoying extra step. ;) I know that it puts it into categories or whatnot. But hopefully the Discussion is in the right interest category to begin with, so it doesn't really matter. So, I don't really see how tagging really matters all that much. :)