In first two “SEO” lessons, we covered the two parts of the internal search engine optimization: on-page optimization and on-site optimization.
In this lesson, we will cover the external part, called off-site optimization. Until some years ago, off-site optimization was nothing more than brute force link building. In fact, if you wanted to rank high for a certain keyword, all you had to do was to use that keyword extensively in the body of your website and to get more backlinks than your competitors.
Over the time, Google made its algorithm more and more sophisticated, and today off-site optimization is a more complex process. The first thing that you need to understand is how the PageRank algorithm works, and we explained that in the previous lesson.
In this lesson, we move beyond the PageRank and talk about the other external factors that you need to keep in mind while optimizing your website for search engines.
The PageRank of each page on the web is basically the sum of the value of all the links pointing to that page. The value of each link, in turn, is weighted by dividing the PageRank of the page where the link is coming from by the total number of outgoing links on that page.
Despite being important, however, the PageRank is only one of the factors that is considered under the Google search algorithm.
There are many link factors that do not affect PageRank directly, therefore, but that will still influence the search rankings of your pages. Below we will cover them individually.
1. Link Anchor Text
The anchor text (also called link title, link label or simply anchor) is the visible, clickable text of a link. If you take a look at the HTML code, the anchor is the part that goes between the link tags. For example, on the following link:
<a href=”http://www.domain.com/page1/”>10 Tips to Save Money</a>
the phrase “10 Tips to Save Money” is the anchor text.
The anchor text of your backlinks is one of the most important off-site optimization factors because Google uses it to identify the content of web pages and files. On their original research paper, in fact, Larry Page and Sergey Brin had a single section dedicated to the anchor text factor. Here is a quote from it:
The text of links is treated in a special way in our search engine. Most search engines associate the text of a link with the page that the link is on. In addition, we associate it with the page the link points to. This has several advantages. First, anchors often provide more accurate descriptions of web pages than the pages themselves. Second, anchors may exist for documents which cannot be indexed by a text-based search engine, such as images, programs, and databases.
Suppose that you have an internal page on your website titled “10 Tips to Save Money in a Recession,” and that your target with that page is the keyword “tips to save money”. Quality backlinks pointing to that page using the phrase “tips to save money” as their anchor text would help your search rankings tremendously.
Be careful, however, to not over-optimize the anchor text of your backlinks. Since this factor has a lot of weight on the algorithm, Google is always watching over websites that try to manipulate it.
The first mistake that people make is to get most of their backlinks with the desired anchor text. In the example above, if the web page in question had over 60% of its backlinks using “tips to save money” as their anchor text, it would raise suspicion and possibly get the page filtered or penalized in the search results.
The natural pattern would be a wide variety of anchor texts. Some people would link to it with “10 tips to save money in a recession”, others with “save money in the recession”, others yet with “check out this article” and so on.
Unfortunately, there is no defined percentage that you should aim for. On some situations having 50% of your anchors with your main keyword will be fine, while on other situations it might raise a red flag and get your page filtered out or penalized in the search results.
For example homepage of a website might have over 80% of its backlinks using the same anchor text, which is the name of the site, but that is what search engines expect in that case. The important thing, therefore, is to make sure that your anchors look natural.
The second mistake is to have “forced” anchor texts around. If your website is called SuperCars.com, for example, it would be weird if some bloggers linked to your homepage on their Blogroll using the anchor text “cheap car accessories.” Anyone with basic SEO knowledge would know that such anchor text was forced there, either because you paid the blogger or because the blogger is your friend and is trying to help you.
If you want to play safe, just remember that bloggers and webmasters often link to web pages using the title of those pages or some phrase that describes them. If you craft your titles wisely, therefore, you will naturally receive links with keyword-rich anchor texts.
2. Relevance of Linking Page
Links that come from highly relevant pages will be weighted more heavily in the algorithm (in the search algorithm, not in the PageRank one).
Suppose you have two pages, A and B, that talk about finance. Page A has 10 backlinks from finance related pages while page B has 2 backlinks coming from finance related pages and 8 backlinks coming from completely unrelated pages (e.g., health and fitness, cooking and online poker). If we then assume that both pages have similar content and that the value of all the backlinks is the same (i.e. the linking pages have the same PageRank and the same number of outgoing links), we can say that page A would probably rank higher than page B.
3. Relevance of Linking Website
Apart from the content on the individual page that is linking to you, Google will also take into consideration the topic of that website as a whole. If you have a finance related website, a link from another finance related website will have more value than a link from a cooking related website, all other things being equal.
The topical relevance of the websites linking to your website or to its internal pages can also be a sign of an unnatural linking pattern. If your website is about finance, but 90% of your backlinks come from unrelated websites, search engines could get suspicious.
4. Relevance of Surrounding Text
Most modern search engines will not only take into consideration the topic of the page that is linking to you and the topic of that website as whole, but they will also analyze the text surrounding each link.
If the words found there are related to the content on your site, you will gain some points. This is even more important when the anchor text of the link is “click here,” because Google will pass part of the anchor text value to the surrounding text.
This factor will also affect the indexation and ranking of your images.
5. Link Age
The older your backlinks, the more value they will have, because the higher the chances that such link was a natural endorsement. Paid and spam generated backlinks come and go much faster, hence why search engines need to weight link age.
Also, keep in mind that it takes some time for a new backlink to achieve its full value.
6. Link Variety
Most SEOs agree that each web page has the ability to cast only one vote for another web page. If page A links twice to page B, therefore, page B will NOT receive twice the value.
The same principle applies to websites as a whole. While two or more links from website A to website B will still have value, as long as they are placed on different pages, each new link will have a smaller value.
If you want to maximize your link popularity, therefore, you should aim to get as many different websites (i.e., root domains) as possible linking to you.
7. Global Link Popularity
The previous point is particularly important to grow your global link popularity, which is the sum of the value of all the links pointing to all the pages on your website (including the homepage).
The global link popularity will influence the search rankings of your individual pages both because the PageRank value will flow naturally across your website, and because a strong global link popularity is a sign of quality content.
This factor explains why most Wikipedia pages, for example, rank really high despite not having many external backlinks pointing to them.
8. Rate of Acquisition of Links
Google and other search engines will analyze the rate at which you gain new backlinks. This can affect you both positively and negatively.
If month after month your website receives thousands of new backlinks, for instance, search engines will see a pattern there and give you more trust.
If your website only receives a dozen new backlinks per month, however, and then on one-day hundreds of backlinks pop up, your website might get flagged. This doesn’t mean that you will automatically get penalized, but Google will take a closer look at the origin of those backlinks, to make sure that they are not paid links or the result of black hat activities.
This factor is particularly important for new websites. Webmasters that start full blown link building campaigns right from day one tend to get problems.
9. Low-Quality Links
Generally speaking, external links from low-quality websites won’t affect your search rankings negatively. Search engines need to adopt that policy, else it would become too easy to sabotage a competitor. All you would have to do is to create some spammy websites and link to your competitors.
If you have too many low quality or spam related backlinks, however, you might be penalized for it. For example, it would be a bad idea to hire one of those “12,000 directory submissions for $59″ services for your newly created site, because this would give you a big influx of low-quality links, and since your site is new those links would be the majority.
When link building, therefore, go for quality rather than quantity.
10. Community Authority
It is very easy for search engines to spot topical communities on the Web. For any given topic, they know the influential websites, popular blogs, legitimate e-commerce sites and so on.
The more backlinks you have from those sources, the higher your community authority will be, and this can positively affect your search rankings.
- Use the link analysis tool to check the anchors that your backlinks have. You can also use the tool on your competitors or on the websites ranked in the first positions of Google for your target keywords.
- If your website is new, be careful not to build links too hard. A gradual and natural approach is always optimal.
- As a long term strategy, aim to get backlinks from as many different root domains as possible.
- Remember that links from relevant websites are particularly important.
Previous Lesson: The PageRank Algorithm
Next Lesson: Targeting Highly Competitive Markets and Niches