For those of you that have a blog then you’re probably used to getting lots of spam comments on your blog.  It’s easy enough to install a comment spam plugin and avoid the worst of it but there are always some that get through the net.

Moderating comments is effective but time-consuming and frustrating for your blog community.  If you have a popular blog then it takes a huge amount of time to manually filter out the spammy ones from the legit ones but still manage to keep an active readership.

As a results, it’s quite common to see lots of spammy comments (and pingbacks) on a blog – especially towards the end of older posts, but it’s easy to assume that they’re not causing any problems except for perhaps looking a bit shoddy.

However it can be harmful.

Mozilla Penalised

Search Engine Roundtable ran a story about Mozilla (the creators of the Firefox browser) receiving a Google penalty because of “user-generated spam”: i.e. lots of spammy blog comments.

I took a look at some of the pages that had been spammed and sure enough the comments were full of keyword rich titles linking back to poor quality sites.  The interesting thing though is that the links were nofollowed, which I thought would mean that Google would ignore them, so I was surprised that Mozilla was penalised.

Then yesterday, it turns out that the spam in question (despite the rest of the site also being full of spammy comments) was only on one specific page, yet those links are also nofollowed.

So Google has applied a manual penalty to that page because it had an (admittedly huge) number of spammy comments despite them being nofollowed.

There are a couple of interesting things that come out of this.

1. Google sent a very vague message to the website owner saying that a manual penalty has been applied to the website due to spammy user generated content.  But it didn’t tell the site owner where that content is.  I know why Google does this – they want you to clean up the entire site, not just the page in question.  So they get you worried enough that you go through your site to clear the whole thing up just in case…
2. Google then came out and told them exactly what page is causing the penalty.  This is very unusual and not the treatment that a typical site owner could expect.  In Mozilla’s case they have millions of pages so probably needed a pointer, but for you or I, we would just have to flounder around in the dark until we do enough to get the penalty removed!
3. Nofollowing a link is no guarantee of avoiding a penalty.

The last point is the most important.  You have to actively ensure that your blog is clear of spam otherwise you may be penalised.   The Mozilla example is extreme – 12MB of spammy comments isn’t typical, but it does signal the direction that Google is travelling in and you have to make sure that your website is as clear of spam as possible – nofollowing isn’t enough.

This penalty won’t have affected Mozilla in the least.  The page had nothing on it except for a load of comments so to have that page disappear from the results isn’t a problem at all.  But if you have an old page on your blog that is still sending a lot of traffic and it is steadily acquiring lots of spammy comments then beware.  If you’re using WordPress then it wouldn’t do any harm to check out your comments via the dashboard to see what’s been going on.

If Google finds a page that it thinks is not adding any value then it may well penalise that page and send you a suitably scary message.  But don’t expect to be told what page is penalised – unless you’re Mozilla then you’ll have to find out yourself!

*Creative comments image by Shawn Carpenter