Thoughts on discussion
In today's world of social news aggregation websites, ala Reddit, Digg, Slashdot, it is rare for the sole dialog between an author and a reader to take place on a private channel or on one's website. I discovered this rather bluntly when I found that a document I had written had amassed a number of comments, one of which pointed out an error in what I had written, and then failed to notify me.
These days, there is a certain amount of savvy that needs to be exercised in order to keep track of references on the Internet. Google Alerts, Twitter search, pingbacks... the list goes on and on. If you want to engage in a conversation with someone on the Internet, you'll probably have to go to the medium they responded on, abide by the social conventions of that site and also risk being totally ignored (although that's not as bad, since "you got the last word.") If you're a small company working carefully to cultivate good public relations around your product, you may even go as far to track down someone's online identity and send them an email asking them if there's any way you can help (it has been described as "creepily awesome customer service.")
Then there's also the flip side of the coin: to engage in a dialog with your reader, they need to know when you've responded! If they commented on their favorite social news site, they'll get an update stream aggregating all of the other discussions they may be participating in. If they commented on the blog itself, options are far more varied: some blogs (like mine) offer no mechanism of notification when replies have been posted; others may offer "email notifications of replies" but fail to distinguish threads of conversation; some even outsource their discussion to a third-party provider like Disqus.
There are, of course, some who have lost faith in statesmanship over the Internet. Those are the people who you'll see post essays with only a private email link for one-to-one conversation; those are the people who force their readers to unsponsored discussion on their favorite social media website; those are the people who shake their heads when the an ignorant commenter fails to display any indication that they read the article or know what they are talking about. I think that we can do better, because I've seen better! (Wink.) I've seen people comment, not because they want to project an image of smugness or superior knowledge, but because there is an earnest dialogue going on between all parties which, most of all, is focused on the transfer of knowledge. I've seen it happen on the Internet; I've seen it happen in real life; I still fall victim to the impulse to posture and chest-beat. I prefer conversing to people when the goal is to communicate, and not to win an argument. I enjoy arguing with people when I feel there is as much listening happening as there is talking. I love having an audience that consists of people, not an anonymous Internet.