From the discussion here, I conclude this quote is widely accepted among those who provide quality discourse: "I try to comment when I have useful, unique, original, or non-standard things to say." This represents a desire to deliver a certain promised value. When you post on a forum, (or send an email, for that matter) you are making an implicit claim: is worth the audience's time to read your post.
For users like me, there is friction in posting because I have to convince myself that I've satisfied the implicit claim. For others, I assume, this friction is absent. So add it artificially: somehow make the claim explicit.
Maybe require posters to select from a list of categories (e.g. Useful Information, Insightful, Civil Disagreement, ...), explicitly claiming their post meets that criteria. Or, less restrictive: a required checkbox that simply reminds you of the claim you're making with your post.
For users like me, there is friction in posting because I have to convince myself that I've satisfied the implicit claim. For others, I assume, this friction is absent. So add it artificially: somehow make the claim explicit.
Maybe require posters to select from a list of categories (e.g. Useful Information, Insightful, Civil Disagreement, ...), explicitly claiming their post meets that criteria. Or, less restrictive: a required checkbox that simply reminds you of the claim you're making with your post.