From the moment Google first launched out of a Stanford dorm room, the innovative technology that separated Google from poor search engine alternatives was the PageRank algorithm. As we all know, this innovation it introduced was in determining the popularity of a web page for the purposes of search results ranking based on the relative number of links pointing to it.
Central to extrapolating the terms and search position for which the URL should rank, the Google algorithm looks at the anchor text contained within links. For example, numerous links to http://www.buy.com/iphone with ‘iphone’ in the anchor text signal to search engines that the page should probably be ranking for the query ‘iphone’.
Optimizing anchor text remains a central part of SEO. In SEOMoz’s annual ranking factors survey, SEO professionals put page level link metrics as the most important ranking factor (together with domain level link authority features) used by search algorithms.
How Websites Implement Anchor Text
Given how important anchor text remains in determining search rankings to the present day, we were curious to see how a broad selection of websites and implemented anchor text across their websites. We looked at more than 100,000 inbound links across more than 650 e-commerce and non-ecommerce domains, ultimately analyzing more than 4.2 million links and their anchor text using Conductor's Searchlight SEO platform (disclosure: I work for Conductor).
We first looked at how websites deploy anchor text by looking at a distribution of anchor text by number of keywords. We found more than half (53 percent) of all anchor text were short and fairly non-specific, containing between 1-3 keywords. The percentage of anchor text peaked at 2 words, declined steadily until 7 words, and then shot up to 14 percent for 8 or more words.
The bump in percentage of anchor text with 8+ words was likely due to inbound links pointing directly to specific products. The analysis showed many inbound URLs with 8+ anchor text were highly specific product descriptions, such as ‘celestial seasonings lemon zinger herb tea 20 tea bags’.
21% of 1-3 Word Anchor Text Links is Garbage or Contains no Text
Our further analysis of anchor text with between one and three words shows one out of five were likely not helping sites to rank. 21 percent of links were either URLs and did not contain any anchor text at all, or were ‘garbage’ text such as ‘gfh5bhfryu’. Despite it being an ‘SEO 101 no-no’ many sites are still committing the anchor text sin of ‘click here’ or some variation thereof—a non-trivial percentage of the ‘garbage’ anchor text were ‘click here’.
Anchor Text Best Practices
Given how significant anchor text remains in determining relevancy for search engine algorithms, and knowing a significant part of inbound links with anchor text is outside of our control, it's important that SEOs take steps to influence the elements that they can control.
Here are some best practices to keep in mind when working with inbound links:
- First Find Out Where Your Inbound Links are Coming From: Today, technology solutions, from full featured SEO platforms to free link analysis software can tell you how where your inbound links are coming from. You can then go after low hanging fruit of instances where linkers may be willing to tweak non-descriptive anchor text to better reflect the page they are ranking to thus helping you to rank for relevant terms.
- First Impressions Matter: The first instance of linking to the same page is often the text used in determining search ranking factors. This factor often occurs in internal linking situations when linking to pages within your own domain, e.g. having a sidebar link to your homepage, and another link to the homepage in the body of your text so keep that in mind as you are developing a linking strategy for your keywords.
- An Image is Worth (Almost) 1,000 Words: The search engines use the ALT tag of an image link to determine relevancy for ranking images. Don’t forget to optimize your images as they are another opportunity to show up in search for your keywords. Research has shown that universal search results (including images) have become increasingly prevalent: one study showed 8 out of 10 high volume searches now have universal results of some kind.
Don’t Forget our Old Friend, Anchor Text
With all of the ongoing changes in the SERPs these days it’s easy to lose sight of the fundamentals of SEO that remain the core of increasing natural search visibility. SEO professionals believe anchor text is still the number one ranking factor, but our analysis of inbound links shows given the way anchor text is used across many sites, there may be opportunity for marketers to optimize their own internal links and target low hanging fruit of non-optimized inbound links from high-value targets.