One question on the mind of many SEO professionals and bloggers is whether or not to NoIndex archive taxonomies in content management systems. Many content management systems have taxonomies for author archives, date archives, categories, and tags.
WordPress is the most popular CMS and blogging platform in the world. While it is great out-of-the-box, it does come with many flaws. The biggest being the massive amounts of duplicate content it creates.
WordPress tends to create over a half dozen duplicate copies of posts if all taxonomies are used. Since WordPress is used on most company blogs and used to create many company websites, I decided to run an experiment on NoIndexing WP taxonomies.
Of course, it would be unethical to try this experiment on a client website, so I used a series of personal blogs within my network. I used four variables to test the results of NoIndexing taxonomies. Before the experiment, all four blogs had all taxonomies enabled for indexation and none of them had optimized pagination.
Traffic growth had been slow and sluggish on all four sites. On variable one, I NoIndexed all taxonomies and left the pagination unoptimized. Variable two had optimized pagination, but all taxonomies were allowed to be indexed. Variables three and four had both optimized pagination and all taxonomies set to NoIndex.
Variable One: NoIndexed Taxonomies and Unoptimized Pagination
For the first variable, I used www.midwesternadventures.com, which belongs to a good friend of mine. Although the website has undergone a redesign recently, many elements, including the pagination of the website, were written in jQuery with the old design during this experiment. This made way for a perfect un-optimized pagination, NoIndex variable since it would be difficult to crawl the pagination anyway. Google’s index of the site continued to remain steady despite shallow crawl depth.
Google’s index of midwesternadventures.com
Within two weeks of NoIndexing the taxonomies, organic traffic plummeted by nearly 20 percent, while Google’s index of the website remained stable.
Since the pagination was written in jQuery and GoogleBot has a hard time crawling jQuery, the crawl depth of the website was very shallow and all pages not linked from the homepage began dropping dramatically in organic traffic, since authority was not being passed along properly between each post.
After two weeks of starting the experiment, I decided to redesign the site and optimize the pagination since traffic dropped so greatly. Traffic skyrocketed after the redesign and optimization.
Variable Two: Indexed Taxonomies and Optimized Pagination
The second variable was www.thetravelpixie.com, which belongs to the same friend. The only thing I changed on this site was optimized pagination. Since the site still had massive amounts of duplicate content from taxonomies, organic traffic growth continued to be sluggish.
Some days it would grow by 3 percent, while other days it would lose 3 percent. Having optimized pagination alone didn’t have much effect on traffic. Google’s index continued to grow as a result of the optimized pagination, but traffic remained sluggish.
Variables Three and Four: NoIndexed Taxonomies and Optimized Pagination
The third and fourth variables yielded the most interesting results of all variables. Variable three was www.bizarreworldfoods.com, which is a site me and the same friend run together. Since it is still a relatively new site, I felt it necessary to run a second variable in this category.
The fourth variable was my own Chicago food blog, www.hgjones.org, which is a well-established site. Within a few days of optimizing the pagination and NoIndexing all taxonomies, Google’s index of the sites plummeted.
Google’s index of hgjones.org
Although the index of variables three and four plummeted, organic traffic skyrocketed. Traffic on variable three increased by 30 percent within two weeks, while variable four increased by 20 percent.
Organic traffic of hgjones.org
As a result of this experiment, I discovered that NoIndexing taxonomies and optimizing pagination will give a massive boost in organic traffic within a few weeks of implementation. Google and Bing recently placed duplicate content in their crosshairs with recent algorithm updates. It is important for webmasters to avoid duplicate content, and to ensure taxonomies are not causing a lack of growth.
Optimized pagination takes the place of taxonomies in crawl depth, so including the rel=prev and rel=next attributes are vital to optimizing taxonomies.
WordPress Plugins Used
I used two WordPress plugins for this experiment, which I highly recommend anyone running a WP site to use. The first plugin I used is called WP-PageNavi, which adds optimized pagination links using the rel=prev and rel=next attributes. This plugin may require some code implementation, but the plugin developer provides all code needed.
The other plugin I used is called WordPress SEO by Yoast, which is the best SEO plugin available in my opinion. Many webmasters will also use All-In-One SEO, which I personally believe is inferior to WordPress SEO. Yoast’s plugin has import controls for importing All-In-One’s settings into WordPress SEO. Instructions for migrating to WordPress SEO can found here.
To NoIndex taxonomies with the WordPress SEO plugin, go to your WP dashboard and click on SEO in the sidebar. Select Titles &Metas. On the General tab, check the box to NoIndex subpages of archives. On the Taxonomies tab, check the box to noindex, follow categories, tags, and format. On the Other tab, check the box to noindex, follow author archives and date archives. Unless you have multiple authors, I would also recommend disabling author archives completely.