I am confused about keyword density, let me say I have a 400 word article and a 4 word keyword. So If I want a %10 keyword density. What will be the result? Is it? 400/100*10/4= 10 I mean so the article normally should have 10 times 4 words keyword on a 400 words article with a density of %10 ? Is it 10 times? Thanks...
Uh, appears that your math is right. But have you read the recent development of too rich of keyword density causes Google to view it as duplicate content and penalizes you for it. At this point in Google's algorithm it's hard to say what is good density and what is too much. Personally, I would focus on the content to your visitors, not just the words. If that makes any sense.
IMO, you want to keep in mind the keywords you are targeting but not focus on them in your content. If you are writing naturally your content will have an acceptable keyword density.
Maybe I'm being cynical, yeah I am, but it really doesn't matter. Just write your articles and design your pages the way you think is best. Google may: index it today or tomorrow, or 9 months from now, deindex it in 2 months, replace it with an older version that no longer exists, reindex it and put it on page 89 in the serps, then put you in the top 10 for 2 weeks, then ban you. Just take the above scenario and repeat to infinity. And there you have the Google algorithm.
But what if your site is strictly an ecommerce site with lots of images? I do have a few articles that are linked to the home page, but otherwise it is mainly products. This is what I have always pondered: how to add content when you want your viewers to focus on the products you have available. I have tried to make the other content as natural reading as possible, but sometimes I wonder if in targeting keywords, I am overdoing it for G. However, Y & MSN love me!
I'm not sure I'm following the math in your example, but 400 words of content containing 4 keywords would be a keyword density of 1% (4 / 400 X 100). The general guidlines for keyword density dictate 3% - 6%, but I agree with other posters that it's much more important to make your content readable and valuable to your visitors. Having a lot of images shouldn't hurt you, provided that that's your content - adding alt text that includes your keywords can help in your SEO efforts. HTH, Sam