Where your backlinks come from is important, as is the anchor text that is on the link itself. The environment from which your link comes will also have an effect on how powerful the backlink is when it comes to your website rankings. Here is an explanation of how co-occurrence and co-citation work to help your SEO (Search Engine Optimization).
The anchor text of your backlink
This is the text that goes over the backlink when it is pointed at your site. Old anchor texts used to say “Click here”, but more optimized anchor text is going to say something such as, “Find pet samples here.” The anchor text does play a part in your SEO. Google uses it to figure out what your website is about, which is why it is a good idea to have one of your stronger keywords appear in the backlink anchor text.
Your website about pets would benefit more from a backlink that contained the words “pet” or “dog”, etc. But, the link would be even better if it came from a website article about pets. The backlink would be even better if the website were older, well maintained, well attended, and mostly about pets. These are just a few of the environmental factors that affect a backlinks power.
But, your keyword environment is able to affect your backlink power, without much help from the anchor text. That is where co-occurrence comes in.
All about co-occurrence
Let’s say that your backlink has anchor text that points to your pet’s website. The anchor text does not have very helpful anchor text such as, “Find the best ones here.” That is not very descriptive on its own, but in the context of the web page it is in, it may make a lot of sense. The anchor text may also be missing a strong keyword, which would be something such as “pet” or “animals.”
But, even though the anchor text is not helping with regards to keywords, your backlink may still be associated with a strong keyword. If the page that it links from is all about one of your strong keywords, then Google may associated the link with that keyword, even if the same keyword is absent from the backlink.
Here is an example: The backlink points to a PC gaming website. The article it links from is all about World of Warcraft and tips on how to level up quickly. The PC gaming website has tips, walkthroughs and cheats, but the backlink anchor text simply says, “Dungeon maps” on the anchor text. In this case, Google may associated PC gaming with the World of Warcraft game and article. This means that even though the backlink does not contain the words “cheats” or “tips”, Google may still associate that link with cheats and tips.
Check the important places for keyword ideas
If you want to know if keyword co-occurrence is possible, then look at where the backlink comes from. Look at the title, URL, words in bold, subtitle, etc, and look to see if any of your web page keywords are present. If they are, then that page has been optimized for those/that keyword. If your web page is also optimized for those/that keyword, then your backlink with the useless anchor text may still be worth something to your SEO.
All about co-citation
This is the idea that if one web page links to a number of similar pages, then the links are grouped as having one theme. It is hard to explain, and is not an exact science. The idea exists in order to lessen the effect of link spam.
Think about it like this: when you look at a Wikipedia page it is often about one idea, thing, event or concept. At the bottom you will find a bunch of references and links to those references. If you were a search engine then you would guess that all the links in the reference section have something to do with the page topic. That is what co-citation is all about. If your link was within those reference links, then Google would assume that your web page is similar in theme to all the other links in that reference section.
Stopping spammy sites
Co-citation is not an exact science because it would cause a mess if it were. If you were writing an essay, you would reference as you go. But, one reference in one paragraph may have a drastically different theme to the reference in the next paragraph. If Google associated all links on a page with your essay on it, then it would turn into an indexing nightmare.
If a web page has a page full of links that are not really related, then the co-citation rule would make each backlink less powerful. If the web page was full of links that were related, then the links would become a little more powerful (albeit tarred with the same brush).
Kate Funk is working as a freelance writer at http://getanycontent.com where everybody can control and coordinate content writing process, from choosing your own writer to accepting or rejecting the final work result.