There are people who sell “comment writing services”. Here’s one: “I will write and post 20 intelligent and relevant comments on authority sites on your behalf for $5″

There are armies of lowly-paid folks in third-world countries creating such “intelligent” comment spam.

Here’s a sample of the sort of comments that would be posted by these services…

• “I coulden’t have said it any better my self, the author know what he is talking about. I can tell from the comments above that most people agree to.”
• “Well, I believe that clears up a few issues for me. How about anybody else?”
• “This is such a wicked site you have. I have bookmarked it, and will come back many times. Your website has been a great guide. Thanks.”

If I didn’t use comment moderation, these would have appeared on my blog.

I’ve not approved these comments because:

1. They don’t add anything to the conversation,
2. They would make just as much sense if they had been added to the post before this one or the post after this one,
3. Their sole purpose is to create a link back to the spammer’s website which too often will be a source of malware. I wouldn’t like my readers being lured there.

I do not recall ever censoring a comment just because it was negative. Have a look around; you’ll find many examples of negative comments that have been approved. Let me know if you would like me to point some of them out.