Article marketing is a highly effective form of link building for search engine optimization purposes (SEO)
. Typically you will not hear anything about keyword density unless the articles are specifically being written for and distributed for SEO purposes.
Article distribution sites are aware of this. They are also aware at how keyword stuffing makes articles seem unnatural and ineffective.
Why Add Keywords to an Article
For links to be beneficial for SEO purposes they must be on a webpage about one or more of the keywords your website is targeting. If you own a pizza shop a link on a car website has little value to you for SEO purposes. A link on a page about pizza would have value.
Article marketing, by definition, means your link will appear on a webpage about the product or services you sell. The fact is you will be adding a link to a webpage you wrote (or had written) because that is how article marketing works.
You want your article to contain the keyword or keywords you are focusing on. Search engines "read" content and give value to links from pages that include the same keywords as someone is searching for.
Article marketing for SEO purposes must include keywords.
How Many is Too Many
It is important that your articles be well written. If you overdo the keywords in an article it will generally appear awkward and therefore lose their effectiveness. Additionally, search engines view keywords stuffing as unethical and will devalue any links from pages that are overly stuffed with keywords.
As a general rule of thumb you want your keyword density to be 3% or slightly under. If you go too much higher you may not get your article approved by the article distribution site and even if you did the article may not be picked up by other sites.
Another danger with keyword stuffing is turning off the reader of the article. SEO experts know that though the articles being distributed are primarily for SEO purposes there is still a good chance that a potential customer may read the article.
An awkwardly written article can turn off the reader and hurt your company's reputation. Make sure you do not sacrifice the quality of an article for a quantity of keywords.
If you keep this in mind you should be able to write effective articles within a 3% keyword density.