It seems there's a new kind of spam around (though maybe not that new... I've been noticing it for a while now and just got around to posting about it). Normally we think of spam as junk email, or if you have a blog or a message forum, you might see an automated script that posts links to a site selling V1agR/\ or something similar, with no relationship to the rest of the discussion.
This new spam, though, is much more insidious, and if you read quickly you might completely miss it. Take this example, which was posted to my article Proper Loading of Toilet Paper, II:
As you can see, the content of the post is somewhat relevant to the article, and it sort of contributes something to the comment thread.
Upon closer inspection, it becomes obvious that this is spam. The link at the bottom is clearly the main point of the message, which is trying to drive up the search engine results of that web site. However, the rest of the message is very context specific to the main article, which leads me to conclude that this is not perpetrated by an automated script, but by a human who is probably getting paid to post messages like this.
Judging from the spelling and the slight misuse of words, one can assume that this person is probably not a native English speaker. You can then make the leap and conclude that there's probably a company in a low-wage country who contracts out services to do exactly this sort of thing. With people getting paid to do silly things like gold farming for online games, it's not hard to imagine that this could be the case.
I've also seen something similar on a few of the larger message board forums. Someone will go through every thread in a forum and post a reply to each one that simply restates what others have said. In this case, the suspicious links are included in the signature of the poster, which can be changed and immediately cause that link to appear on every post made by that user. The giveaway for this type of spam is that the time-stamps on the messages are often very close to one another. This could indicate that someone is methodically going through each post instead of thoughtfully reading and replying to each message.
With messages that are almost relevant to a post, what's a blogger to do? On one hand it's pretty clear that it's spam, but on the other the messages can often be more relevant to a topic than what a "real" reader might post. So what do you do here? Do you delete the whole message? Do you leave it there? How about editing it just to remove the spammy parts?