Basically when you are optimizing for SEO, you are going after keywords also called a keyword phrase that people type into google and other search engines and your webpage comes up. There is whats called on-page SEO as well as off-page SEO. Keyword stuffing is when you constantly are using your main keyword as well as other related or LSI keywords all throughout your content. This is part of on-page SEO
I have found that around 2, 3% for my main keyword with variations lightly sprinkled throughout the whole content has worked best.
I hear Google is coming out with another update here shortly to go with the last one they just had.
This post has been edited by Ethan P.: Jul 30 2013, 06:52 PM