I don't think any commenting system has that feature. You're thinking about something that automatically integrated with FB/Twitter/etc? So if someone posts a c

I don't think any commenting system has that feature. You're thinking about something that automatically integrated with FB/Twitter/etc? So if someone posts a comment about your blog post at FB, it appears on your blog too? (I saw your reply & clarification to someone else below.) I suppose if there was a way to do that, FB and Twitter would dedicate some time to stop & prevent & break that feature, because they want the discussion to happen at their place instead :- ( Maybe a text message asking the user to please cross post, could do some good? (but not much I suppose) I've been thinking about if FB, Twitter, etc could be used as notification systems, so, if someone, X, posted a comment at the blog, and someone replied a few days later — then X got a notification via Facebook or Twitter. I had a quick look but didn't find a way to do that via FB. (Because then higher likelihood that people go back to the blog, reply, and continue discussing with each other.) I was going to ask what blog commenting system you use, and say that if you added Facebook or Gmail login, maybe more people would post comments, since they wouldn't need to sign up and create an account, just to post a comment. — But now I had a look at a blog linked via your profile, and I see you already have FB and Gmail login.