Should I manage a collection of links to related content on my site?

While links are an integral part of the web, maintaining large collections of links on your site:

  • Does not provide value for your customers
  • May hurt your website in search engine rankings
  • Requires more ongoing effort than maintaining content
  • May violate the letter and/or spirit of Penn State Policy AD52

Link Farms

We refer to a page or section of a site containing a collection of links as a "link farm". Prior to approximately 1999, search engines were not very powerful, and one of the main ways people found new content was through lists of links on a site.

Search Engines

More than a decade later, search engines are much more powerful, and are the most common way people find content. For the AgSci sites, 60% of the traffic comes from search engines.

Since search engines automatically index your content (and the rest of the content on the web), we're duplicating that effort by creating your own index of other sites' content.

Instead, the way we can best help the public is to provide original information that search engines can direct people to. For example, our Entomology fact sheets consistently receive the most traffic of any information in the college precisely because they provide unique information.

One of the metrics that Google uses to rank pages is the number of links to that page or site. When linking to another site, Google credits a tiny bit of your "search engine karma" to the other site. A reasonable number of external links won't hurt your site's rank, but a site that's composed of 80% external links and 20% content will not show up high in search results.

Maintenance, "Link Rot"

When linking to external sites, "link rot", or links gradually breaking over time is a problem. Other sites will change their URL structure, and one of the downsides to creating a "link farm" is the constant maintenance of your external links.

Broken links on a site create a bad user experience and negative user perception, and search engines penalize sites with many broken links.

Original Content

Creating original content may take more time initially, but it has a huge benefit for your site, rather than the tiny penalty associated with an external link. Search engines direct people to original content, not to indexes of other sites' content.

The Google Analytics data for our sites show that most users are looking at real content, such as:

  • Factsheets (Entomology, Turf)
  • Guides (Tree Fruit Production Guide, Fruit Production for the Home Gardener)
  • IT How-To's
  • Ice cream nutritional information

Penn State Policy AD52

AD52 states:

It is the policy of the University to limit commercial links to those sites that have a direct connection to the functions of the University, and to prohibit commercial links that are unrelated to the operations of the University.

While this doesn't prohibit external links, it reinforces our recommendation that links should be limited, and closely related to the purpose of the site.


External links aren't inherently bad, but we should concentrate on producing relevant original content. When providing external links, you should pick the 2-3 most relevant links rather than 20-30 links of questionable quality. This is more beneficial to the user, and easier to maintain.

Our sites should be a destination, not a catalog of information on other sites.