I agree with guidelines but don't agree with the number of characters in a post. We have already demonstrated on a small example why a short post can be constructive. I'd say introduce maximum number of posts/users per campaign and minimum rank required to join a campaign. This should somewhat reduce the spam.
FTFY
BTW, now that I think of it, even my own argument that many people would leave bitcointalk if short posts or signatures aren't allowed, seems stupid, seeing how well Quora is doing. Not much logical thinkers in bitcoin community I guess