Keyword density, proximity, repetition — placing your keywords properly can be a major part of an SEO campaign. It’s easy become overwhelmed and obsessed with finding the perfect words or phrases to fit your pages, then cramming keywords in.
A basic guideline we give our clients is a keyword density of 2% – 4% per webpage, meaning a keyword or keyphrase should only appear four times or less for every 100 words. Anymore than that, and search engines may flag the page for spam. Four-percent may not sound like a lot, but you can try it for yourself. Read a selection of text with a keyword density of 5% or more out loud to yourself. You may be surprised at just how “spammy” it sounds, or how difficult it is to read.
It’s important to remember that good SEO is more than trying to find the right amount of words in the right order to gain the attention of a search engine. Many other factors come into play and keyword density is just one of them (and it’s not even the most important one). When you look at a few of what Google considers to be important factors in SEO, like inbound links and the growth of social search, you can see that quality content is what earns high rankings.
When developing content for your site, try not to obsess over keywords. Instead, focus on creating compelling content that people will share. Always remember to optimize for the user, not the search engine.