There is a distinct difference between providing content that is rich with relevant keywords and providing content that overuses the keywords. Content that has a keyword density that is too high may be flagged as illogical by search engines. As a result your website may be penalized for word stuffing. Also, if your content is virtually saturated with keywords, visitors are not likely to see the benefit of your content. If visitors do not think your website is useful, they are not likely to return and they are not likely to create back links to your website.
Is there such a thing as too many keywords?
How do I get more links pointing to my site?