1. First all of if you are writing articles for traffic you are really not concerned about duplicate content. As a matter of fact, the more directories your articles are in the better chance you have to increase your traffic.

This seems like common sense because the more eyeballs you have on your articles the more chances you have for them to click on your website address in your resource box. If you are limiting yourself to one article directory, you have limited the potential amount of traffic from that article.

2. Secondly then we have to consider are you writing for search engines? It is important that you have unique articles targeting different keyword phrases if you are writing for search engines.

Obviously the more unique articles you have targeting unique phrases, the more chances you have to rank on individual pages within a search engine. You do this by submitting unique articles to as many different directories as possible.

The problem with this is it can become time consuming to constantly be rewriting articles and manually submitting them one at a time to individual directories. For this you may want to consider the Article Leverage Program with an outstanding submission company known as SubmitYourArticle.com.

The link to the article itself is one other factor to consider. Different submission services are looking for different lengths of articles. Generally speaking, your articles need to be 400 words or more, if you are going to use a service to submit them.

Even manually submitting one article of 400 words to four or five of the top directories is a good idea as opposed to just limiting it to one.

If you want to write shorter articles in the 250 word range you may want to post those on your blog as well as submit them to Ezine articles.com. Doing this, you can bookmark your blog post to use as search engine bait, as well as use the article itself for traffic from EzineArticles.com.

Ultimately you may come up with a system of your own that combines various things depending on how you are going to use the article.

So the question of how many article directories should you submit to becomes a personal one based on how long your article is, who you are targeting when you write it, and where you are submitting it to.