I've thought a lot about comments. I've never had many comments - so few, in fact, that I no longer make the effort to support comments on my website. The same with distributed comments - I don't see many responses on Twitter or elsewhere. Even in the days of mailing lists, I wouldn't get many responses to my emails - I always just figured I had closed the discussion with the correct answer, so there was nothing else to say. Someone once said to me that everyone knows everyone else has read it, so there isn't much to add. I used to comment more than I do today, but my tolerance for logins, passwords and capchas is almost zero. Anyhow, this article talks about the flavours of comments. I don't know - I see websites with long comment threads and I'm still not sure what makes people comment on one website and not another.