Originally Posted by Nutty
There is no probably NO optimal kewyord density, I do not think keyword density is used as a metric, keyword prominence, placement and repetition is most definitely a factor at some level.
I stopped using keyword desnity some time ago and instead I concentrate on keyword placement on the page using a rule of thumb, 3 instances of a keyword in the page copy as a minimum plus one for each additional 100 words I write
Keyword density is only a local weight. The fact that a word appears many times on a specific page doesn't help much in telling what is the page about when comparing it to other pages in the index, keyword density is easily manipulated by enough repetition.
I agree to this, Keywords density is no doubt a very important factor but making a definition for it is not correct. The keyword density varies from need to need. Unnecessary keyword stuffing can not be described as keyword density. Everyone should judge the need of keyword repetition from user prospective also. Too much use of keyword could irritate the reader and they would find it repetitive and useless.
The best solution could be the proper use of keyword which will be beneficial from search engine as well as user point of view.
For more examples we can search various web pages, blogs and informative article that could help to decided keywords density for your web page content.