Does Keyword Count Affect Ranking?

Most SEO professionals will tell you that the number of times a keyword is repeated on a page (keyword count) and the ratio of how often that keyword is used in relation to other text (keyword density) are minor search engine ranking factors. However, they will then go on to tell you to be very careful not to go over the "limit" or your site will be penalized. What is the limit? How many times should you repeat your keyword? You usually won't get that answer from your friendly neighborhood SEO, because they simply haven't done the study to find out. We have. Enjoy the results.

The methodology: I gathered the results of the queries I naturally performed last month using the leading search engine and analyzed them. I had to visit each page and count the number of times the keyword was used in between the body and /body tags. Those keyword counts were then tabulated for the first 10 rankings and converted into a normalized "ranking correlation".

The resulting number shows each group of keyword counts (grouped in ten's to reduce the amount of data required for a valid statistical analysis) normalizing into a number between ~100 and +100 showing the likelihood of being ranked higher/lower. A value of +100 shows that all 10 rankings were in the proper order to show that pages of the studied size ALWAYS rank HIGHER than pages of another size. A value of ~100 shows that all 10 rankings were in the proper order to show that pages of the studied size ALWAYS rank LOWER than pages of another size. Numbers in between show the varying likelihood of rankings proportionally between ~100 and +100.

That is the number you see on the Y-axis. On the X-axis, we have groups of keyword counts varying from 1 to 130. I stopped at 130 because the number of sites found with keyword counts higher than 130 were too few to consider statistically valid. Here is the graph:

There is no natural shape to the resulting graph. This probably indicates that the leading search engine does not actually use this factor directly in their algorithm. However, the general trend is upward. There appears to be no cut-off point where pages with more keywords are ranked lower. If such a cutoff exists, it is more than 130 repetitions of a keyword.

There are two interesting peaks. The first is between 11 and 20 repetitions of the keyword. This is probably the most useful peak for normal pages (articles, paragraphs of text, etc.) since pages with 1-10 repetitions of the keyword rank so poorly in comparison. The next peak of the graph is between 81 and 90 repetitions of the keyword. Wow! See if you can get your SEO to guess how many keyword repetitions is "too many". I'm willing to bet that they will say something far less than 81 repetitions.

Notes:

1. Over 1,000 queries and over 10,000 sites were examined for this study.

2. There was no exercise to attempt to isolate different keywords. I merely took a random sampling of the queries I performed during the month.

Conclusion:

Pages with their target keyword repeated 11-20 times or 81- 90 times rank best on the leading search engine! If there is a "cutoff" point where too many repetitions of a keyword result in much lower ranking, we didn't find it. Pages with up to 121 repetitions of the keyword continue to rank higher than pages with 1-10 repetitions of the keyword.

This is merely a correlation study, so it cannot be determined from this study whether the leading search engine purposefully entertains this factor or not. The actual factors used may be far distant from the factor we studied, but the end result is that this search engine does, in fact, rank pages with the above keyword counts higher than pages with other keyword counts used in the study.

Jon Ricerca is one of the leading researchers and authors of the Search Engine Ranking Factor (SERF) reports at SearchEngineGeek.com. For access to the other SERF reports, please visit: http://www.SearchEngineGeek.com