Co-Citation, Co-Occurrence…Co-What?

Link-building, as we know it, is dead; so dead, in fact, that the funeral was six months ago and everyone has more or less forgotten who link building was. What were we talking about again?

Well, that’s how the theory goes at least. In truth, link building remains one of the most important factors in SEO – it’s just spam link building en masse (i.e. links from all-encompassing directories, spammy blogs…you know if you’re doing it) that has largely bitten the bullet.

Nevertheless, with Google’s algorithm evolving intelligence at a rate that suggests self-awareness within a year (and the employment of futurist Ray Kurzweil suggests Google fancy having a bash at achieving technological singularity too), it’s worth taking a look at a few SEO methods that rely less on ‘technical’ factors such as links and treating Google’s beloved algorithm as more of a human.

Kind of like a really bad ‘fish out of water’ comedy movie starring Robin Williams as the Google Algorithm and us as the put-upon family having to deal with ‘the hilarious consequences’ of binary code (represented by Robin wearing a suit adorned with zeroes and ones) trying to do the washing up, or dish out relationship advice to a teenager.

One of the ways we can treat our new pal Google Algorithm (he prefers ‘Algo’) in a more human manner is to consider our online marketing tactics from a more human perspective. Common sense, innit? There are some well-publicised post-Penguin and Panda methods of doing this; what would a human reader determine to be quality content? Would a human expect a link to your site about carrots to appear on an online gaming site? And what would such a link make them think of your site?

As I’ve already said, these methods have been repeated ad nauseum in post-Penguin and Panda link-building guides. One area less covered, however, has been the Co family; co-citation and co-occurrence.

What are Co-Citation and Co-Occurrence?

Co-citation and co-occurrence are often confused with one another (including by Rand Fishkin, proving that even the best of us make mistakes) and with good reason; they’re pretty similar concepts.

Co-citation, summed up here by Jim Boykin, is a Google ranking factor used to determine subject similarities between two pages based on links from a third party page. So, for example, if I was to link to both SEOMoz and Search Engine Land, that would be a co-citation and a signal to Google that the two sites have similar subject matter. While a single occurrence won’t have much effect, if enough sites link to those two sites, the strength of the relationship between the two increases.

Image Credit: Search Engine People

While this may not be particularly beneficial to two already authoritative sites such as SEOMoz and Search Engine Land, if people were to continuously link to SEOMoz and Fluid Creativity, Google would begin to associate our site with SEOMoz and thus our status as an SEO authority would increase (as if it wasn’t astronomical already).

This, of course, also works in a negative manner. If enough sites were to link to SEOMoz and a spammy Viagra site then SEOMoz would take a hit.


Co-occurrence is similar to co-citation but rather than associating two sites, it associates a site or brand with particular phrases, based on how many people refer to that brand and phrase in close proximity. It’s important to note that co-occurrence is only a theoretical ranking factor but one that’s gaining some credence, as demonstrated by Rand Fishkin in this Whiteboard Friday video.

The theory of co-occurrence goes that when someone impartial discusses a brand and what they do, Google forms a link between the two. So if someone was to write about Fluid Creativity and wrote ‘Fluid Creativity is a digital agency in Manchester’, the algorithm would associate ‘Fluid Creativity’ and ‘digital agency in Manchester’. Even if the author didn’t link to the Fluid Creativity website.

Enough of these occurrences across other websites and Google would associate the two phrases to an extent that we would rank for digital agency in Manchester, even if none of those pages linked to our site and we didn’t have any backlinks with that particular anchor text or performed any other optimisation for that key phrase on the page.

Of course, all of this is theoretical- it’s well worth taking some time to read these posts by Bill Slawski of SEO By The Sea and JoshuaGiardino for the ins, outs and patents relating to co-occurrence and rankings.

What Co-Citations and Co-Occurrence Can Do For You

So we’ve got one ranking factor that’s been around for years and another that is purely theoretical – how are they going to help you rank #1 for your keywords? Well, in truth, they may not. What they will do, however, is set you on the right track and hopefully increase your traffic in a manner that won’t see you get banned six months down the line.

Let’s look at co-citations first. Considering the concept of co-citations when link building is the perfect way to determine whether a link opportunity is right for you, whether it be a directory or a potential guest post opportunity. Take a look at other sites the site is linking to; if it’s predominantly sites in niches related to our own and they’re relatively authoritative, go for it.

If the site is linking to completely unassociated sites, then think twice. There will of course be cases where a site will link to sites about many different topics, such as news sites, but blogs that include topics on anything and everything – as well as directories that link to anything and everything – should be avoided. The odd link off these sites won’t necessarily tie your music site to poker or cricket, but enough random links will. Also consider what a human would think about seeing a link to your music site next to a link for a site selling Viagra; not great, is it?

Co-occurrence offers some more interesting prospects. The key to co-occurrence is to get other sites talking about your brand in the context of what it is you do; you can do this through blogger outreach, social media or even good old fashioned press releases. While building this association won’t necessarily improve your rankings, it will lead human readers associating your brand with what you do, which in turn could lead to increased traffic and even some natural, rank-boosting backlinks.

Co-occurrence is also important if you’re running a local SEO campaign; if you’re a florist in the Rochdale area, and the Rochdale area is your predominant market, you’ll want to be reaching people in Rochdale. Make sure that when sites are discussing your brand, they’re also mentioning your location.

Instances of co-occurrence can also help your site generate traffic for keywords you haven’t optimised for, such as synonyms. Let’s say you’re selling bread rolls and have optimised your site and built links based off ‘bread rolls’ but forgot about ‘cob’, ‘barm’, ‘bread cake’ and the rest of the infuriatingly long list of names people call a bread roll.

Through co-occurrence, your site can build authority for these terms – press releases sent to Northern news sites, for example, could cover ‘your brand’ and ‘barm’ while a press release sent to West Bromwich could cover ‘cob’ (forgive my errant geographical placings of the various names for bread rolls – correct me in the comments if you want!).

And then, of course, there are the big ‘what if?’s. What if Google is about to unleash an update that places extra emphasis on co-citations and co-occurrences? What if Google is already using context as a ranking factor along with quality? What if Google decides one day that backlinks and anchor text are too easily manipulated and calls time on them all together?! All hypothetical situations (with some being more likely than others), but it certainly doesn’t hurt to be prepared, does it?

So co-citation and co-occurrences; there’s a lot of speculation and theories surrounding them but their importance doesn’t necessarily just lie in their ability to get your site ranking; they can improve your visibility to customers and help you reach wider markets you might not have considered before too!

  • Written by on 31st January 2013 at 11:05
  • “Fluid Creativity is an award-winning, multi-service digital agency based in Manchester.”
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  • Brett Tudor

    I think there may be a few digital agencies who are sweating on what happens next when it comes to backlinks. For now just doing a quick search for seo companies in Manchester or Liverpool brings up websites that have 30,000 plus backlinks from only a few sources. It looks like Google still rewards those websites that have backlinks in huge volumes, but for how long I wonder?

  • Brett Tudor

    I think there may be a few digital agencies who are sweating on what happens next when it comes to backlinks. For now just doing a quick search for seo companies in Manchester or Liverpool brings up websites that have 30,000 plus backlinks from only a few sources. It looks like Google still rewards those websites that have backlinks in huge volumes, but for how long I wonder?