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Almost nearly all about link incongruity

Posted by Michael Martinez on February 12, 2008 in Link Theory

In The Relevant Link Myth I wrote that “it is virtually impossible to acquire an irrelevant link.” Yesterday I wrote in Link Analysis Done Right:

Relevance is not very important if you’re just looking for crawling, PageRank, or anchor text but it sure helps if you want to maximize the value of your link building efforts. The more relevant links you have from high traffic Web sites the more likely you are to get referrals from those sites and the less dependent upon search traffic you become.

In concluding The Relevant Link Myth I wrote:

When you’re studying a Web site’s backlink profile, don’t ask yourself how relevant the links are. Ask yourself how useful the sites linking to the destination really are. You’ll most likely find that the “useful content” test is a far better indicator of quality than the “relevant content” test.

Useful content is always more useful than useless content but you have to define “useful” carefully. Most people might say that “a page simply filled with links is not very useful” unless they are talking about a page in DMOZ or the Yahoo! directory. Those pages were once considered highly useful by searchers and link builders alike and they continue to be highly coveted linking sources.

Context means just as much in link placement as it does in conversation. A link can be helpful to a lot of people or just helpful to the destination page. And there is nothing wrong with a link that only helps the destination page as long as it is a useful link. That is, it needs to help the destination page as much as possible, in as many ways as possible.

Link context can be expressed as incongruity. The less relevant a link is to the page on which it is placed, the more incongruous the link is. The less relevant the link is to the destination page, the more incongruous the link is. Many people in the search community will use deliberately incongruous anchor text in order to avoid passing link anchor text to destinations. Matt Cutts has done this on his own blog many times.

For example, I could tell you about this Web site without passing any anchor text to it (other than the word “this”). The anchor text is completely incongruous because it doesn’t express a complete idea and therefore has no relevance to either my own blog post or the CNN Web site.

Link congruity only exists when a link’s anchor text (or other text associated with the link) expresses a complete idea. But the expressed idea is still incongruent if it clashes with the ideas expressed in either the linking or the destination page.

People in the SEO community place incongruent links all the time. In the past incongruent links passed value as much as congruent links but now search engines look at link congruence in one way or another. “Another” meaning there are other factors that may cause a search engine to filter out a page’s links without having to determine that the links are incongruent.

However, where one link may be completely incongruent two links (expressing the same or similar ideas) are less incongruent. If you put enough links (which by themselves would be completely incongruent) on a page, the link collection makes the links more congruent (because the link collection is a component of the page’s logical and semantic structure).

Link congruence diminishes as a link’s associated text becomes more closely associated with the rest of the indexable text on the page. Hence, a properly classified link on a directory page is always congruent.

The value in thinking about link congruence — for search engine optimization — comes in understanding how useful a page may be to the casual visitor. The more incongruent links a page carries, the less useful the page may be to casual visitors simply because there is no focus in linking topics.

Linking topics are the subjects of the outbound links. If you have good focus in linking topics you at least provide your visitors some value. That is, you could write a really short, brief, relatively uninformative blog post but include 10 links to greate Web sites. I’m sure you have seen many such blog posts. Links from such posts provide the only value in those posts and those links are congruous (although the congruity may be more figurative than literal depending on the post).

A page with only internal links (navigational or cross-promotional links that only point to other pages on the same site) still has linking topics and the internal links may offer strong linking topics or poor linking topics. This is why it’s better to link to your home page with the name of your site or business or your own name than to use the anchor text of “home”.

When you treat links as content you create them with more care. You can place a link on a page and make it congruent to that page by writing sufficient text to explain why the link is on the page. I call such link placements “sidebar links” because I usually embed them in the margins of pages as part of sidebar articles.

You can improve the congruence of your inbound links by acknowledging them. You don’t have to reciprocate the links. You just need to add some text to your page that agrees in topic with the text conferred by your inbound links. This is very similar to optimizing for the long tail of search by adding copy that includes expressions people use to find your content.

As with all things you can take link congruity too far. Autogenerated spam pages, for example, tend to scrape content that is heavily loaded with specific keywords. Autoscraped pages are pretty easy to identify algorithmically because they use fragmented, broken text snippets that really don’t have anything to do with each other. Since all the text is incongruent, all the links tend to be incongruent.

Some spammers are autogenerating huge long nonsense paragraphs, again building them on the basis of keyword selections. These types of spam pages tend to be self-incongruent just as much as the jangled messes of snippets. When the linking source itself is completely incongruent, there is little to no value for any of its links — they cannot become congruent with nonsense.

Link congruence is therefore closely associated with text congruence. You can have two unrelated, irrelevant-to-each-other, but perfectly sensible text blocks on the same page. News sites do this all the time. So do blogs. The incongruence between text blocks is natural but each block of text is congruent within itself.

In this aspect, congruence is the same determined by coherence. Incoherent text is incongruent. Hence, by extension, incoherent links are incongruent. So if coherent text is congruent the coherent linking structures are also congruent.

Generally speaking, the more work you put into creating the link (by placement, context-building content, etc.) the more congruent, coherent, and useful the link becomes.