Much Ado about Anchor Text

As SEOs, I feel like we often focus too much on specific ranking factors to the detriment of other factors that might be equally important. One particular case I want to point out is the obsession with incoming link texts, also known as anchor text.

Thanks to some very successful Google bombings, it is almost general knowledge among site owners that getting enough links with the desired keyword in the link text is a surefire way to get high rankings for a site in Google. This also applies to any search engine that relies on link analysis. And while Google has devised advanced filters to reduce this vulnerability, I think that as long as link analysis plays a fundamental role in their ranking algorithms, the practice of Google bombing will always have some effect.

Here today, here tomorrow

Will Google ever get rid of the anchor text as a ranking factor? I don’t think so. As documented in “The Anatomy of a Search Engine,” anchor text helps not only to qualify what the page is about but also to search for non-textual information (binary files, e-mail addresses, etc.) or temporarily inaccessible URLs.

This idea of propagating anchor text to the page it refers to was implemented in the World Wide Web Worm [McBryan 94] especially because it helps search non-text information, and expands the search coverage with fewer downloaded documents. We use anchor propagation mostly because anchor text can help provide better quality results.

But the anchor text itself is not the be all end all for the search engine. Some of my SEO peers might not know this, or simply prefer to ignore it, but the fact is that the text surrounding the links is also a good indicator of what the linked page is about. It is particularly the case when the text in the link doesn’t provide enough clues, such as when you use “click here” as the link text. As I am sure some will ask how I know this, let me offer some evidence that backs up my claim.

6.1 Future Work

… As for link text, we are experimenting with using text surrounding links in addition to the link text itself. A Web search engine is a very rich environment for research ideas. We have far too many to list here so we do not expect this Future Work section to become much shorter in the near future

Here Google’s founders describe their intention to use of the text surrounding the links in addition to the link text. This was almost 10 years ago. Of course this does not prove that they are currently indexing the text surrounding the links as well. But check out this reference: Bill Slawski blogged about an interesting patent related to Google’s personalized search technology: "Personalizing anchor text scores in a search engine”. Of interest to our discussion is the description of the anchor text indexer:

An anchor text indexer 217 is responsible for generating an inverted anchor text index 211 from the links in each document received by the server 210, including the text surrounding the links. The links and corresponding text are extracted from each document and stored in records identifying the source document, the target document associated with a link, and the anchor text associated with the link. When a sufficient number of such records have been accumulated, an inverted anchor text index 211 is generated, mapping anchor text terms to the documents that are the target of the corresponding links. In some embodiments, the inverted anchor text index 211 is merged with or incorporated in the inverted content index 208. More information about anchor text indexing is provided in U.S. patent application Ser. No. 10/614,113, filed Jul. 3, 2003, "Anchor Text Indexing in a Web Crawler System", which is hereby incorporated by reference.

As Bill mentioned, it would be really interesting to get access to the referred patent (Ser. No. 10/614,113), which is unfortunately not published publicly yet. It would provide far more detailed information on how the whole anchor text indexing works and how it is used when searching.

Conclusion

The bottom line is that there are clear indications that search engines (at least Google) use the text surrounding the link in addition to the link text as a relevance indicator. This just makes plain sense when you think about it. It also means that we shouldn’t worry too much, or be so obsessed with, having the keywords directly in the link text. Having keywords in the surrounding text might provide the same benefit.

Don’t be afraid to use “click here” on your links every once in a while. Besides providing click-through advantages, it can help make your link profile look natural and avoid search engine filters. Just don’t forget to use your keywords in the surrounding text!