@rustybrick I won't presume to speak for @martijnvdven, but if he's had the same experience I've had with @disqus, their system tends to mark anything with a useful link in it as spam and one's (considered) responses are thus moderated out of existence. It's far better to write and own your response on your own site as he has.

It looks like @martijnvdven's site sends and receives webmentions (a W3C recommended spec), so if @seroundtable's site did (or Disqus did on its behalf), then the comment would exist both on Martjin's site as well as SER's as well.I suspect that since your site doesn't, he used Twitter to push across the notification so you'd be aware.

It might be more useful for @seroundtable to provide links to portions of their conversations/content (like the one I'm replying to on Twitter) syndicated to other platforms like Twitter on the site (similar to the way you did for the "forum discussion"), so they're easier to find and participate in--especially for those who don't want to sign up for a Disqus account.