As with most aspects of ranking that can easily be manipulated, Google nowadays is somewhat smarter than it used to be. In the past, you could make a ton of links to a site with the anchor text “blue widgets” and you’d rank your site for “blue widgets” as #1, if you had the most powerful back links. Then Google changed and started to penalize sites whose back links carried too large a percentage of the same anchor text.
There are two levels at which Google is punishing sites for having too many back links with the same anchor text — at the site-wide level, and at the page level. If your site has (just for the sake of example) more than 80% of its back links with the anchor text “blue widgets”, then it may incur a penalty. And if a specific page has (again, just for the sake of example) less than 30% of all its back links with the anchor text “white widgets”, it might avoid the penalty.
After this penalty was implemented, SEOs quickly found new ways to bypass or even manipulate the new algorithm. Using so-called LSI keywords, which is just a fancy name for synonyms or related keywords, you could rank for the same search term, and as an added bonus, you were now ranking for many related search terms.
Thus we arrive at the current implementation, where surrounding text is also taken into account to determine the relevance of the link to the page. Example: if the surrounding text (probably 1-2 paragraphs) is about “blue widgets” but the link, embedded in the middle of that text, has the anchor text “nose hair” then it will provide less benefit than a link embedded in the same text with the anchor text “blue widgets”. It’s very hard to determine if those “nose hair” links actually contribute to your page getting a penalty if the anchor text is irrelevant. But why waste linking power, anyways.
In order to reduce the percentage of occurrences of the same anchor text with the goal of avoiding the penalty for overuse of a specific keyword, SEOs have started recommending that you use bare links (i.e. only the http://site.com) or useless anchor text like “click here”, “visit”, “nice site”, etc.
While there is strong evidence that so-called keyword stuffing (where an unnaturally large percentage of your anchor text is for one keyword) will lead to a penalty, there’s no strong evidence that you need to waste opportunities to provide information to Google about what your link is about, in order to avoid penalties. In other words, it’s not clear that using “click here” and other such anchor texts is a requirement. However, naturally built back links do sometimes have those anchor texts, so, to make your back links look more natural, you might include them every so often.
Whew, this is a long lecture, and you’re probably asking yourself when he’s finally going to tell me how large a percentage is safe — how large a proportion of your back links can have the same anchor text. Well, the answer, unfortunately, is — I don’t know. SEOs know it’s easy to incur a penalty with 90%, 80%, and even 60% of your back links having the same anchor text, if the total number of your back links is above several hundreds. What we don’t know is how large the percentage needs to be to incur the penalty. There’s strong evidence that 20% of all back links having the same anchor text is pretty safe.
* Until a specific page has >100 back links, you can probably use four-five different anchor texts and you’ll be safe.
* When the page accumulates >100 back links, start to diversify the anchor text with LSI keywords, useless keywords, bare links, and so on.
* Site-wide, when your site has at least 100 back links, you want no keyword to occur on more than 20% of all back links, site-wide.
Next time a controversial subject — is back linking black hat?