10 tips for identifying blog comment spam

Posted by Ben on August 26, 2009 | Permalink | Hits: 2154 
Tags: comment spam, keywords, abuse, foreign characters, symbols

< 10 ways to fight spam | Comments | Spam prevention tips: 10 blog comments you should deny >

Back in February, I listed 10 ways to fight spam on your blog. Unfortunately, unless you completely shut off comments on your blog, there's not really a way to stop spam completely. With that in mind, here are some tips that may help you to identify whether a comment is spam or not. Again, it's not a perfect guide, but it might just help you. Let me know in the comments if you found the post useful.

(Today's post is accompanied by a photo taken by Helmetti.)

1. Keywords in the name field.

Some commenters don't use their real name. Others prefer to use keywords instead of any kind of name. Think of things like "Low Energy Light Bulbs", "Texas Home Renovation", or my personal favourite - "Wallpapering Weekly Newsletter". Actually, I made those up. Anyway, keywords can be a good sign that the commenter is just hoping to get a link from your site to theirs.

2. Generic appreciation.

The "nice post" discussion is a bit of a running joke around here. You can see where it all began in my first post on this blog - 10 signs your blog sucks. Still, that aside, some spammers seem to like saying nice things about your blog. All they're doing is trying to convince you that their comment should go on your blog. Again, it often means they'll get a link from your site. If a comment says little more than "wow, nice post... I'll be back to read more" ... dig a little deeper. You might find that the person concerned is not as sincere as you might think.

3. Comment length.

Is the comment really, really long? Or abnormally short? As with all of these points, it's not a guarantee, but sometimes the length is a giveaway. I've seen some amazingly long comments that didn't contain anything except links to dodgy sites. Some really short ones, too - with just one solitary spam link.

4. Same IP, different comment.

If you keep getting comments from the same IP address, it could be someone who really likes your site - or it could be a persistent spammer. Keep an eye on the IP - it isn't completely reliable, but in some cases it can be quite revealing.

5. Same comment, different IP.

At the other end of the scale, watch out for identical or very similar comments posted from a variety of IP addresses. This suggests that the spammer thinks they can change their IP to evade detection. There's a fairly simple solution. Delete the lot.

6. The same comment appearing on lots of different blogs.

Have you just had a comment that seems OK but you're not entirely sure if it's genuine? Simply Google the first sentence, or part of it, and see what comes up. I've uncovered loads of spam by using this method. Don't let the situation perpetuate - trash the comments.

7. Bizarre, nonsensical comments.

Sometimes, I think non-English spammers try to write something that is proper English, but it doesn't always work out that way. One of my least favourite comments is "Thanks for this post, very informative and positively". I didn't miss a word. It ends with "positively". There's not much point listing other examples as they keep changing - just watch out for comments that don't make a whole lot of sense.

8. Check the URL.

Sometimes, a relatively innocent comment has a really nasty URL attached to it. The problem is that it's best not to visit it - but how do you know it's bad unless you do?

Some URLs are clearly spam - just read the text. Does it lead to a blog? Is it a really long URL that appears to be some kind of referral or affiliate link?

Also, beware of comments that leave absolutely no URL. They are difficult ones to deal with, as the comment itself might be absolutely fine, and with no URL - why delete it? However, this trick is used to get a comment up so the same person can post some spam without it going into the spam queue, or even into moderation. Be careful - and make sure you get notified of every comment that's posted on your blog.

9. Foreign characters and symbols.

When I see a mess of weird symbols, I probably delete it in less time than it took the spammer to post it. Keep an eye out for those. Also watch out for comments that seem to include three or four different ways to post a URL using a link or url tag. These seem to do the rounds in a format where one or two of the links should work, but different formats work on different systems. This is very much a cut and paste comment, not something that the writer actually wrote for your site.

10. It goes into the spam queue!

When all else fails, you may find some comments just end up in the spam queue and you can't figure out why. Or maybe you can. But do keep an eye on which comments go into the spam queue, and remove any that shouldn't be in there. This gets harder as your blog grows, but can be achievable if you stay on top of it.

What do you think? Can you think of any other ways to identify comment spam? Do you agree or disagree with any of the above tips?

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Comments on 10 tips for identifying blog comment spam

7

Ben | August 27, 2009 | 207 comments

Thanks for the feedback everyone!

9

Ben | February 27, 2010 | 207 comments

Ann, happy to help!

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