Google: Comment Spam Can Hurt Your Site's Ranking

Nov 27, 2009 • 8:33 am | comments (8) by twitter Google+ | Filed Under Search & Web SEO Spam

Google wrote a blog post named Hard facts about comment spam. I'll sum it up for you quickly. If you do not protect your site against comment spam, Google will trust your site less and it can ultimately hurt your rankings.

Most blogs these days have automatic comment spam solutions, but you need to make sure your blog is handling it correctly. I check comment spam here several times a day. Although most gets caught, some leaks through and I need to take care of them manually. Yes, I have them all nofollowed anyway, but comment spam looks bad and it distracts from the content on this site. I am more concerned with it distracting from the content here then Google trusting me less - too be honest. But most bloggers are more concerned with Google trust over reader trust, so either way, this is something you need to take care of.

How does this hurt your rankings? Well, if Google trusts the links on your site less, then your internal linking power dwindles down and you rank lower.

Google offers these tips:

  • Disallow anonymous posting.
  • Use CAPTCHAs and other methods to prevent automated comment spamming.
  • Turn on comment moderation.
  • Use the "nofollow" attribute for links in the comment field.
  • Disallow hyperlinks in comments.
  • Block comment pages using robots.txt or meta tags.

There is a lot of discussion around this blog post at Google. Some seem surprised by this, while others do not.

Forum discussion at DigitalPoint Forums and HighRankings Forum.

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David Iwanow

11/27/2009 02:12 pm

One of the many reasons you should be using a solution such as Wordpress it does most this automatically. Reasons that many people continues to advise clients to use wordpress as it helps you follow best practice.

Jim Rudnick

11/27/2009 03:49 pm

great piece, Barry....that comments MUST be policed for sure! :-) Jim

Michael Martinez

11/27/2009 07:15 pm

And yet many people in the SEO community continue to share lists of so-called "dofollow" blogs. It's no wonder why many people think SEOs are nothing but spammers.


11/27/2009 11:44 pm

So can it harm you or not? I wrote something that is in slightly in contradiction to this: Curious to see what others think. PS: Of course SPAM is bad. But can it hurt you? Competitors can do it to harm your rankings as it's easy enough.

Bill Kruse

11/28/2009 08:59 am

There seems to be some confusion here over which site suffers from the spam links, the site with the spam links on it, or the site the spam links lead to. Common sense would suggest it's the site with the spam on it, because if it were the other way around then you could, if I read the post correctly, get a competitor penalised simply by relentlessly creating spam links at them. This would invalidate Google's algorithm and thus their business model. However, again if I read this right,"If I spammed comment fields of third party sites, what should I do? If you used this approach in the past and you want to solve this issue, you should have a look at your incoming links in Webmaster Tools. To do so, go to the Your site on the web section and click on Links to your site. If you see suspicious links coming from blogs or other platforms allowing comments, you should check these URLs. If you see a spammy link you created, try to delete it, else contact the webmaster to ask to remove the link. Once you've cleared the spammy inbound links you made, you can file a reconsideration request." then that's exactly what a competitor is able to do, get a site penalised by creating spammy links to it. If the site isn't penalised, why the suggestion then that a reconsideration request be made? I think this is a confused and illiterate posting. I'd be inclined to write it off as obviously nonsensical, no matter its alleged origins. BB

DJ Portis

07/11/2011 06:23 pm

I'm still not sure if leaving comments on blogs can hurt you (e.g. cause you to lose rank) or if because of all the blog comment spam in recent years, they just don't count for much in terms of SEO.  There seem to be some differing opinions and I don't know what the "REAL" truth is.  For example, what if you actually leave a valid, blog related post that adds value to the conversation, but the rest of the comments on that site are spammy?  Does that mean Google will penalize your site because every one else's comments are spam? That doesn't seem fair. Also, as Bill has mentioned above, if Google penalizes you for having a link on a page with a bunch of spam comments from other people, then what keeps your competitors from taking your URL and posting it on all these sites to get you knocked out of the rankings?  That seems like it would create a nightmare for Google if everyone starts purposely posting comments to try and get their competitors knocked out of the SERPS. My guess is that there isn't actually a "penalty" if you leave comments on blogs that have a lot of other spam comments, but they probably aren't worth much, so you probably need hundreds or thousands to give you a boost in the rankings. This is one of the hardest parts of internet marketing.  You never really know what or who to believe because one person will say blog commenting got their site banned and someone else will say they do nothing but blog commenting and get #1 rankings all the time.


08/17/2011 05:35 am

One of the many reasons why you need a solution like Wordpress that makes the most of this automatically. Reasons why many people continue to advise clients to use WordPress because it helps you follow best practices. search engine optimization company

how to earn money

08/26/2011 03:11 pm

I posted my comment policy after reading a post at Lorelle on WordPress suggesting every blog should have a comment policy. I think it’s a good idea—commenters can see you’re not singling them out but following a well-thought-out, established policy. Of course, the spammers don’t read or care about policies.

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