Link Farms

One unsuccessful method of increasing link popularity is by becoming part of a “Link Farm.” Link Farms are networks of sites that have all agreed to link to one another. Each of the sites in the link farm has a page containing links to all other sites that are part of the farm. One of the problems with this strategy is that the content of the sites that are linked together does not necessarily share any common theme. Therefore, even though your site may have a seemingly high link popularity score, most of the links carry very little weight since they lack relevancy to your site. Some link farms have tried to improve on this by categorizing their members and only establishing links between members that have related content.

While this is an improvement, it still does not address the core issue – a link farm is an artificial method of improving link popularity, and most search engine have mechanisms in place to either ignore or actually penalize link farm participants.

A couple of years ago, I attended a search engine strategies conference and someone in the audience asked about link farms. AltaVista’s chief scientist was sitting on the panel of experts and he laughed when he heard the question. He then proceeded to identify several well-known link farms by name and stated that AltaVista did not consider links from sites in those networks to have any validity whatsoever. If a link farm is promoting itself on the web chances are that search engines are already aware of it and will ignore any links form sites that are part of that network.

Why Inbound Links to sites are taken into account

As you can see from the previous section, many factors influencing the ranking process are under the control of webmasters. If these were the only factors then it would be impossible for search engines to distinguish between a genuine high-quality document and a page created specifically to achieve high search ranking but containing no useful information. For this reason, an analysis of inbound links to the page being evaluated is one of the key factors in page ranking. This is the only factor that is not controlled by the site owner.

It makes sense to assume that interesting sites will have more inbound links. This is because owners of other sites on the Internet will tend to have published links to a site if they think it is a worthwhile resource. The search engine will use this inbound link criterion in its evaluation of document significance.

Therefore, two main factors influence how pages are stored by the search engine and sorted for display in search results:

- Relevance, as described in the previous section on internal ranking factors.

- Number and quality of inbound links, also known as link citation, link popularity or citation index. This will be described in the next section.