Comments are at the heart of the web 2.0 media revolution, comments were the first step in familiarizing most online readers with how to write online, turning them from lurkers to participants. Without comments do you really have a blog? Many would argue no, yet as Philip Smith explains in his article, "Comments Are Dead. We Need You to Help Reinvent Them," publishers worry more about trolls than they do about free speech and encouraging discussion.
Philip wrote the article to promote the next Knight-Mozilla Challenge where the crowd is asked to come up with a more dynamic space for online discussions. He does a good job of describing the history and current state of commenting in the publishing industry. One fact he missed was explaining the value of comments to an online publisher in terms of SEO. Comments do provide content which include the keywords your audience may be searching on. And apart from filtering out spam and trolls, that content doesn't have to be edited. In effect comments are a low cost source of content for publishers.
If you are thinking of designing a content garden you'll know the concept is to create a website that generates value through content using paid, commission-based, and non-paid forms of content from writers. Therefore this discussion about the value of comments is important when putting together your content garden; comments should be an important step in your design process. I read Philip's post to get some ideas about why commenting is so valuable, and I will be watching the Challenge process to see what ideas already exist and will be submitted.