Writing your own articles and getting them printed can be free as opposed to paying for Pay Per Click Advertising and the more articles you submit the more well known you will be and the more targeted website traffic you will get. Each article you have published is great advertising for your website as at the end of your article you will have printed an 'about the author' section (also called bylines), this advertises you and your website and builds free traffic to your site and trustworthiness for you if your articles are of good quality.
What I have seen is that some people write a lot of articles, in other words, they basically spam the article directories with low quality articles. By doing a relationship study between the revenue obtained and the number of articles submitted in article marketing, keeping other factors constant as far as possible, it will be possible to measure the quality of the author's writing.
But by themselves they don't put money in your bank - there are a myriad of factors that can turn your article marketing efforts into an opportunity to increase your income, not just the number of visitors to your site. Keep in mind that Article Marketing is not an ad, so you can not just start writing about how great your product or service is but rather supply helpful informative content for readers. You don't even really need to know much about the subject you are writing the article about since there are resources available that you can use to provide a basis that would have enough informatiom in it to get your article started.
It is diffidult to guess which sites will pick your article up, but it can be very exhilarating to find that an article that you wrote has been published by a site with PR (Page Rank) 4 or 5 or maybe better. Investigate and build a list of all the free article directories you can find so that you can simply submit your articles to the sites on your list when you've finished writing. Based on my experience both as an author and a creator of niche focused content sites, think very carefully before leaping on the bandwagon of the newest trend in article publishing.
What I have seen is that some people write a lot of articles, in other words, they basically spam the article directories with low quality articles. By doing a relationship study between the revenue obtained and the number of articles submitted in article marketing, keeping other factors constant as far as possible, it will be possible to measure the quality of the author's writing.