The purpose for writing articles for the purpose of marketing is to create a high traffic for both the article and what it tries to promote. For the purpose of marketing online, article marketing is either the best method followed to date. And these are highly consistent and gather a steady influx of high quality traffic once it is published and well promoted.
The prime question of how this is done arises of course! The answer is that these articles use back links as their main method of marketing. They provide links to whatever the article attempts to promote- the web page for the idea or commodity, and ensures that the reader is interested enough to go on to visit the link.
Having said that, of course you should recognize that whatever you say in your article should cater to the purpose you write it for and should not contain unnecessary or irrelevant material. Remember, people on the net take active interest in whatever you try to promote, as most of them are not people who surf around casually for anything and everything!
Article writing or rather getting articles written for yourself costs hard anything when you compare this to the number of sales the article generates for you. All you have to do is to write the article or get it written by someone and submit it to database distributor companies such as I-Snare and others for your article to be distributed for free. So, write articles and improve your sales, now!