alexa_s is ture about EZA. However, some article website do require you to publish articles on their site first. Like Buzzle.com. And Buzzle is better than EZA in my view. Then what to do. If the first right really matters a lot to google?
If the SEO is done well - it DOES mean you will land high - that is the whole point of SEO. This is not to say that all SEO is created equal - you should find someone with proven results. The backlinking derived from articles is a key component to page ranking in Google. High Google placement is still equal to increased exposure and subsequent sales.
It's safe to submit your 1 unique article in all article directory.. But if I were you I'll just submit it in top 10 article directory..