Submitting free articles is one of the best methods to market your product or to promote other's products "Affiliate Marketing. By submitting a free article you will gain many things.
The first thing you will get is a high targeted traffic from the article directory website. They will publish your article in their library and feeds and they will guarantee your some targeted traffic in short time.
The second thing you will get after submitting a free article is the back links when a webmaster publish your article in his/her website including your author box your a link to your website.
The best action for a success article marketing is that you have to submit your article to all article directory available. Although it is very time consuming, but you will discover that it worth the time.
If you want a helpful tool to submit your article to the article directories, I strongly recommend you to try this tool: http://www.quickarticlepro.com where you can submit your article to hundreds of free directories in seconds.