In part one, I explored the idea of links as the threads of the web, helping both search engines and humans find their way from one site to another. In part two, I explained why search engines look to links as part of their attempt to replicate human judgement so that they can determine the content of the web site or web page.

Today, in the final installment of this series, I'll explain how search engines use links to determine the popularity and authority of a web site.

I've explained before that search engines are seeking to replicate human judgement when they decide how to rank sites. After all, when you are trying to develop a computer system that will deliver listings that will make a human happy, you need to come as close to thinking like a human as possible.

In the off line world, people can tell how popular a product or business it is by noting how many people are talking about it. If all of your friends start talking about a new restaurant that just opened up down the street, you might take notice. If you read a raving review in the newspaper, you might take more notice. If you see that restaurant get featured on the Food Network, you might ask yourself why you haven't visited it yet.

We're used to listening to friends, family and authorities to help us shape our opinion about people, places, products and services.

Thus, it makes sense that search engine engineers would want to program search engine spiders to analyze web sites in the same way. After all, the Internet was built with it's very own system of spreading the word about other sites; the link.

You see, links are put into place for a reason. Usually because the person placing the link feels that the site has enough value to be worth visiting. Thus, links tell a search engine that another human being values your web site. Think of links as a sort of online voting system. Every link that comes into your site serves as a "vote" and tells the search engine that someone thinks your site is worth while.

Search engines have even learned how to place value on the site sending the link. After all, just as you would place more value on a recommendation that comes from the Food Network than you would on an overheard conversation in the super market, it makes sense that different web sites will carry different weight in their recommendations.

So just as a search engine looks at different qualities of the links that point to your site in order to determine how much value to place on it, they also look at the different qualities of links pointing to the sites that link to you. By looking at factors like the number of links, where the links come from, the content of the links and even the age of the link, a search engine can start to judge the value of your site and the sites that link to it.

Links reflect human judgement because links are put in place by humans. Without links, search engines have no way to judge how many people think your site has value, or how much credibility the people that link to you have.

Hopefully, this three part series has helped you to understand why it is that search engines place so much value on links when it comes to determining your web site's ranking. With an understanding of why links matter and what the search engines are using links for, it starts to become much easier to understand how to go about building a solid link campaign and why it's worth taking your time to go after quality links instead of quantities of links.

Discuss this article in the Small Business Ideas forum.

March 22, 2007

Jennifer Laycock is the Editor of Search Engine Guide, the Social Media Faculty Chair for MarketMotive and offers small business social media strategy & consulting. Jennifer enjoys the challenge of finding unique and creative ways to connect with consumers without spending a fortune in marketing dollars. Though she now prefers to work with small businesses, Jennifer’s clients have included companies like Verizon, American Greetings and Highlights for Children.

Search Engine Guide > Jennifer Laycock > Why Links Matter - Part 3