The “nofollow” microformat, intended for use to indicate to search engines that you don’t want this link to be followed, has been the subject of quite a few interesting posts recently. On the one hand, there’s Loren Baker’s 13 Reasons why NoFollow Sucks:

The NoFollow link attribute (rel=”nofollow”) was originally created to block search engines from following links in blog comments, due to the amount of blog comment spamming.

The theory is that if spammers are spamming in blog comments to get better SEO and anchored links for their sites, NoFollow would render such spam useless. Problem is, spammers still spam.

And on the other front, Ahmed Bilal, in response with Defending NoFollow Against Angry SEOs:

Google has taken a lot of flak on a lot of issues in the past few years – it’s a price an industry leader invariably has to pay.

Apart from Blogger spam (and their plans to control all of the world’s information and then sell it to the highest bidder 🙂 ), NoFollow is possibly an issue that gets Google the worst possible press.

But is NoFollow really that bad a move, or is it something that’s being used to beat Google over the head by people who have grudges against Google?

Now, in general, my feelings are that nofollow has proved to be entirely useless as a method to prevent spam. It’s vaguely possible that spam would be 10 times worse today than it is had nofollow not been employed on many blogs by default…but I doubt it. Nofollow, however, does have perfectly valid and understandable uses. Ahmed exposes the most interesting value to the nofollow microformat by pointing out the actual purpose it carries:

Anti-spam plugins prevent spammers from posting spam on our blogs. NoFollow prevents spammy comments from polluting the search engines. There’s an important distinction – Google’s responsibility is to guarantee the best possible results. When did fighting the world’s spam fall under their responsibilities?

NoFollow was never expected to stem the tide of spam: it was, however, hoped to reduce the amount of spam in search indexes, allowing searchers to more easily retrieve valuable information.

Whether that has been a success is, certainly, a very different question. But that is the question we need to analyze in order to determine whether NoFollow has really been of any use, not whether more or less spam has been unleashed on the world; but whether we can find that spam in Google’s search index.

Now, this is a difficult question to test. This is far from the only means that Google uses to stop spam – the fact that you can’t find the spam sites which are being linked to in your spam comments using Google doesn’t necessarily mean that NoFollow had anything to do with it. If you’re anything like me, no spam comment has ever been on your blog long enough to be indexed. So, in order to identify spam which has been blocked by NoFollow, it seems you’d need to confirm the following points:

  1. This spam site has been successfully linked to using the NoFollow microformat.
  2. This spam site has only been linked to using the NoFollow microformat.
  3. This spam site has not been removed from the Google index using some other means.

And I’m not sure whether we can do that. Google may be able to; but I can’t.