People who don’t know much about search engine optimization (SEO) probably still have heard that keywords are important to a search engine’s ranking on its results page. There is little question about that. However, there is much more to SEO than the number of times a keyword appears on a given page. And there is little agreement about what the optimal keyword density is, or even if there is such a thing as optimal keyword density.
The only real certainty is that keyword stuffing (forcing a high percentage of keywords into page content to the detriment of the content itself) is not good and can result in a penalty from various search engines. Just about any search will give you first page results that have widely varying keyword percentages, including, believe it or not, 0%. Over the long term, good content rises above keyword-stuffed pages with little useful information on them.
For example, if you search on the keyword “beekeeping,” the top result, as you see in the screen shot, is the Wikipedia article, which has a keyword density of about 1.4%. The second-ranked search result is http://outdoorplace.org/beekeeping/citybees.htm, which has a keyword density of 0.6%. The third-ranked search engine result has a 3.7% keyword density.
This in no way suggests that 1.4% keyword density is “optimal,” but that there are factors other than keyword density at work in determining search engine rankings. There is no escape from the need for good content regardless of keyword density.