Links are the highways, the connections Google uses to identify the relationship between pages. A page with no incoming links is invisible; it cannot be indexed unless submitted directly. Links are how pages are discovered, how users find them and how they appear in search results.
They’re so important that Google places strict limitations and requirements on their use. Use the properly, and you’ll watch the SEO value roll in. Use them improperly and you’ll be faced with penalty after penalty. One such misuse, in the past, was the link farm. A spam user registers dozens of websites, generally all on the same server for convenience, and links them together. The resulting mass gains significant SEO power due to the interlinking, which it can then direct outward for SEO boosts to other sites.
The problem with the amorphous link mass is that it’s all for the search engines. Webmasters making such a network had no time to attract users and post valuable content. Those dozens of blogs would be filled with robotic content or spun articles. Obviously, this provides no utility to the user, and Google decided to penalize such networks. The way it did so was to identify when sites are hosted on the same IP and drastically devalued interconnecting links.
This solution was not elegant; it was a brute force method that had repercussions against unrelated sites on the same IP linking to each other. Google has since refined its detection, but it leads to the question of the day. When linking between websites on the same IP, should you tag those links as nofollow?
Learning About Nofollow
The way Google works is that it considers each link something of a vote of confidence from the originating site to the destination site. The weight of the vote varies. A small site may put all of its confidence in its links, but it doesn’t have much confidence to pass. A larger site – something like Google itself – could link to the same destination, and its link would have much more weight. This is the basis of link authority and PageRank, among other things. Of course, the weight of this vote can be negative. A link originating from a known spam site will do nothing at best, or be actively harmful.
One problem with this scheme was that Google did not care where a link was place. If you linked to a site in your blog post, and someone else commented on your post with a different link, both links look like they come from your site. This lead to comment spam abuse.
The nofollow attribute was created to combat this and other linkspam issues. Now you can add the rel=”nofollow” attribute to your link code. This tells the search engines that you do not vouch for the content of the destination link. It essentially removes the vote of confidence you might otherwise pass.
The Issue of Link Networks
As mentioned, one of the ways links were abused was by making a large network of interlinked sites to pass link confidence votes to a destination site. This is considered a black hat technique and has been penalized by the search engines. One way in which Google detects such link networks is, again, by tracking the source IP address of the web server hosting the site. Too many sites on the IP, all linking to each other, looks very much like a link network. If all of those links are followed links, it looks even worse.
The problem here arises when you, as a business owner, own several websites. Very likely all of those websites will be hosted through the same company, to save time and money. Also likely is the fact that those sites are probably going to be in related niches, stemming from your core specialty. You post a piece of content on one site which would be valuable to the users of another, and so you link to it. After a while, your sites, interconnected with followed links and all hosted on the same IP, begin to look like a link network.
Legitimate Linking vs. Link Networks
The difference between your legitimate blog network and a black hat link network is the value you offer to your users. When you’re linking to other pages, it’s because you believe those pages will be valuable to your users, even if they’re posted on another site you own on the same host.
For these links, you have two options. Leave them as followed or set them as nofollow.
Leaving the links as followed allows you to pass link juice from one of your sites to the next. In many cases, this is something you would want to do. Passing link confidence gives your target site a boost in SEO. The issue with this is if Google decides that you’re using links to boost your SEO without providing user value, it can penalize you for it.
On the other hand, setting your links as nofollow stops passing link equity. This limits the SEO value of a link to just what you gain from sharing your audience between your sites; a significantly lower amount of value in most cases. On the other hand, you protect yourself from possible SEO penalties from Google when they audit your site link profiles.
Which is the right choice?
From the Mouth of Google
Unsurprisingly, Matt Cutts has addressed this precise issue. Should you use nofollow between related sites on the same IP? The answer is… maybe!
That’s not very helpful, is it? As with most aspects of SEO, the real answer depends on your sites and your links. Here are a few guidelines.
- • If you’re linking to pass value to your users, you’re probably okay keeping the links followed.
- • If you’re linking to a site that is largely unrelated to your originating site, you should probably nofollow the link.
- • If you’re linking for SEO value above and beyond the value to your users, don’t. Nofollow the link or don’t link at all.
- • If your interlinking reaches a level where you’re connecting 50+ sites together, nofollow your links, even if they pass user value.
If you’re only linking a couple of sites, and those sites reside in similar niches where the content shared between them may be useful to a shared audience, followed links are perfectly fine. It’s only when you reach a level where you’re linking dozens or hundreds of sites together that it becomes an issue. That’s when your network ceases looking like a valuable organic growth and begins looking like a black hat link network.