The Ideal Keyword Density
Matt Cutts says . . .
A question I often get asked is what is the ideal keyword density for a given page on your website. For a question such as this, I often simply say that you want to write for humans. After all, Google and the other major search engines need to take proper care of their customers and their customer are humans. Google and the other major search engines actually try to emulate humans. That’s right! They actually try to emulate us.