Comment on Search Engine Robots and Spiders by SEO Guy.
If you are using a keyword for more than 2 to 3 times in 100 words, you may be in trouble with a KW density that’s too high.
The search engines will recognize your content as spam. This will badly hurt your SEO campaign.
So make sure you are not making this mistake and that you are only using the keywords according to the search engine guidelines.
IME a keyword density percentage of around 2% to 3% works best.