Keyword optimization is at the heart of SEO, but its importance is often downplayed. As a result, keyword cannibalization — commonly referred to as keyword blurring — can be a major problem. Most website content revolves around a theme or series of themes, with associated keywords described by a slew of witty terms such as “keyword buckets,” “keyword silos,” or the more down-to-earth “keyword themes.” Websites frequently mix themes and subject matter from page to page. While this may make sense from a user-interaction perspective, it can be counter-intuitive from a search engine’s perspective.
To help clarify the situation, consider the larger entity of “keywords” as having three parts: 1) core word, 2) keyword phrase, and 3) extended keyword phrase. Core words are commonly repeated through many pages on a website, making it difficult (if not impossible) to rank for a core word or one-word phrase via on-page optimization alone. Examples of core words include “book,” “website,” “TV,” or “music.” Keyword phrases are also often repeated through multiple website pages, and this is generally where blurring occurs. Keyword phrase examples include “harry potter book,” “website design,” “JVC TV,” or “rock music.” Extended keyword phrases are less commonly repeated on multiple pages of a site, and often need to be limited to only one page of a website. Some examples of extended keyword phrases include “harry potter and the goblet of fire,” “small business website design,” “JVC 32-inch plasma TV,” or “rolling stones paint it black.”
Now that we’ve established the basic types of keywords, let’s explore some best practices for their use.
On-Page Keyword Use
Optimization techniques for a typical page should focus on 3-5 keyword phrases and at least 5-10 extended keyword phrases. In general, limit the use of extended keyword phrases to one page, and be cautious in how you mix keyword phrases and extended keyword phrases. To illustrate this, let’s assume we are optimizing a music search engine website. The artist page called “Rolling Stones Music” features 20 top Rolling Stones songs, each with their own subpage including song lyrics, ring tones, and an option to buy the song via iTunes. Keywords should not blur from page to page.
Keywords for the artist page “Rolling Stones”
Keyword phrases might include:
- Rolling Stones Music
- Rolling Stones Songs
- Rolling Stones Website
Extended keyword phrases might include:
- Classic Rolling Stones Music
- Top Rolling Stones Songs
- 70s Rolling Stones Songs
- 80s Rolling Stones Songs
Keep in mind that this artist page will link to 20 song pages (songs like “Paint It Black,” “Wild Horses,” “Shattered,” and “Beast of Burden”). The artist page will naturally have some of these song-related keywords within internal links pointing to the song pages, but shouldn’t intentionally target these in general SEO target areas like the page title, meta description, H1 tags, and on-page content. The song pages by themselves are the most relevant landing pages for keywords like “Rolling Stones Paint It Black,” not the artist page. Targeting song keywords on the artist page and the song page creates keyword blurring.
By focusing on keywords, and being cautious not to blur keyword phrases and extended keyword phrases, there is a good chance that Google will reward the artist page with a ranking for song keywords as well, thereby creating a double ranking. Intentional keyword blurring will only confuse the search engines, which reduces the effectiveness of both pages.
Also pay attention to internal linking, as links on a page carry significant weight in the ranking process. Make sure your site links contain keyword phrases and extended keyword phrases, but be sure not to link to a page using keyword phrases targeted on another page. This will only cause confusion to the search engines. As an example, linking to the “Rolling Stones Paint It Black” page should only use the words “Rolling Stones” or a primary keyword phrase being targeted on the artist page (like “Rolling Stones song”).
Content Indexing Best Practices
In addition to being cautious not to blur keywords, ensure you do not dilute your keyword targets too much. Websites with heavy content and user-generated content need to be especially cognizant of keyword dilution. For example, many music search engine song pages feature user comments. If the “Rolling Stones Paint It Black” page features user-generated comments, you may need a strategy to exclude portions of the comments. If the song page has 31 comments, chances are most comments will not use the desired keywords, significantly reducing keyword density. The use of iframes is an excellent way to display this desired content without incurring keyword dilution. My recommendation is to display the first 10 comments only, and then display the remaining comments within an iframe. Be certain to generate these iframes with the noindex meta tag so they are not indexed in the SERPs.
Often a website will have redundant content themes, and might carry the same keyword phrases and extended keyword phrases from page to page. A review process will help uncover potential theme conflicts, using a sitemap or local/server files to determine if theme repetition is occurring. Another option is to view Google’s indexed pages by performing the site: operation search (i.e., site:yoursite.com), which displays all pages indexed by Google for the searched URL. If you find multiple pages targeting the same theme indexed, consider consolidating them down to one page. Multiple pages using a duplicative theme will confuse search engines, and the pages may not rank properly or the wrong page may rank in place of a more desirable page.
If consolidation is possible from a site architecture perspective, then there is really only one way to make your intentions known to the search engines — a 301 redirect of the page or pages with duplicate themes to the primary page you want ranked. A 301 redirect can be achieved in a variety of ways depending on your server operating system, and the web is full of helpful guides to correctly 301 redirect one internal page to another.
Redirecting these pages may significantly improve the ranking of the primary page. Not only will you clean up and correct your keyword use strategy, but the internal pages being redirected may have direct inbound links (i.e., pages on other websites linking directly to them). In this way, the primary page will benefit from both its direct inbound links and the direct inbound links from the redirected pages. Google, in particular, will pass all link popularity credit from redirected pages to the primary page. As a side note, this strategy works exceptionally well if you own multiple websites, assuming each have their own unique inbound links.
Off-Page Keyword Best Practices
Off-page anchor text is still one of the biggest components considered by ranking algorithms. Savvy SEOs ensure that — whenever possible — inbound links point to the appropriate pages and use anchor text found within the on-page portions of the page. No one can fully control inbound link anchor text, but keep a close eye on the backlink portfolio, using tools like LinkDiagnosis.com or Backlinkwatch.com.
If you are engaging in link building activities, also be aware of standard strategies to use to keep your backlink portfolio looking natural. For example, most websites have 50%-80% of their backlinks using some form of branded keywords, and 75% or more of most websites have backlinks linking to their home page. Keep in mind, however, that overusing specific keyword phrases in a link building strategy will generally have the opposite effect to that anticipated and will essentially throw up a red flag to search engines. The acceptable rate of keyword use in inbound links is based on your website’s existing link popularity portfolio, historical link growth rate, and age.
Keyword cannibalization is a frequent occurrence, and is often the underlying problem in an otherwise well-designed SEO strategy. The use of proper keyword optimization strategies on-page and off-page will neutralize blurring and improve rankings. Revisit site optimization every 90 to 180 days, with the above instructions comprising some of the basic rules to follow. Every website and SEO strategy is different, but if you haven’t previously given much thought to possible keyword cannibalization, it might be a good time to evaluate your approach. Good luck!