must be a really long tail keyword with no competition. What is the keyword and which site it is? If you can share it then we can check it out.
As you can see in blog comments now most of them are plagued by spammers that are posting non related statements just to exposed their links. These spammers doesn't really care if the blog sites are no follow or do follow link but as long as they are able to post their links they will.
True, but what about those who post comments for the sake of interaction (while leaving links as a bonus?). Regardless, I do agree that it's mostly done by spammers, and the sites I'm handling are plagued by hundreds of spammy Wordpress comments.