Ditto on the SEO. I don't make money directly from article marketing. The money comes from the effect it has on my SEO.
As a former professional writer (I think that's fair to say), I can't imagine there's a way to make serious money writing articles. If you're really good, it kind of seems like there's a much bigger payoff if you use your articles for your own SEO purposes... If you're just starting out and trying to build a portfolio of work, you have way too much low-priced competition... Sorry.
I agree with SeattleCPA, ezinearti... must be the biggest or one of the biggest of its kind, it hardly brings in 10s of visitors over the lifetime of an sports article on popular subject. An average surfer would not spend time looking for sports articles on free articles site if the surfer can visit sports sites with renome and experts, interviews, pictures such as ESPN, Yahoo Sports. If a person wants a personal touch in that article, he/she will Google for blogs on the given subject. At free articles sites, an average surfer would spend time searching for a sport and subject of interest, need to go through introduction lines, titles... pick in to see the articles that may not satisfy basic professional writing standards, articles with the sole purpose of promotion of someone's site/product under the disguise of an article.. all that on landing pages that are overwhelmed with text/banner ads.