On their own each of these sites offers multiple SEO benefits. Each allows
links to your site with Article Depot and GoArticles allowing Anchor Text in
the body of your article.

The next way that these article submission sites offer a way to gain links
and therefore better search engine results, is that due to their sheer size,
your article tends to get picked up by website owners looking to beef up their
sites. At times a single submission can generate more than 100 links! If you
chose to submit to hundreds of the smaller submission sites, you may get the
same amount of links but it would have taken a great deal more work.