There’s a lot of talk among hardcore bloggers on the subject of the best way to deal with spam in their blog comments. Some people advocate turning off comments entirely; others suggest turning them off after the post reaches a certain age. It seems that comment-spammers mostly focus on older entries–perhaps simply because statistically, most entries are old, but perhaps this is intentional, in the hopes that the blog owner won’t notice comments on posts that have scrolled off the front page.
There’s also been a lot of discussion of power laws and inequality.
How one runs one’s blog is one’s own business, of course, but it’s a shame to disable comments on old posts. Jason Kottke famously had a thousand-comment-long discussion following his review of Matrix Reloaded.
I’ve observed a vaguely similar phenomenon in a post I made after getting my wisdom teeth out. A google search on the phrase “wisdom teeth out” brings up the comments on that entry as the third result. People drop by to relate their own experiences getting their wisdom teeth out: it’s not a discussion, exactly, more a repository of anecdotes, mostly by people I don’t know and have no other contact with. Obviously this couldn’t happen with closed comments.
What’s also interesting is that this must be a self-reinforcing tendency. I have no way of tracking how the same comments page has been ranked in Google’s results over time, but I can’t imagine that it has always been #3. The more people that comment there, though, the more that page is likely to be ranked highly as a result for wisdom-tooth-related queries.