Have you use article submission to promote a website successfully? I have not tried it, my reasoning being if you submit one article to multiple location, its not unique any more so there will be little or no SEO benefit but perhaps I am wrong?
I only ever submit to one, or sometimes two article sites, never more.
Although the article is no longer unique, especially if ezine publishers or other webmasters decide to use your article, it should mean that you get the benefits of those people pasting not just the article but your links as well. They are required to display all links in order to be able to use your article (though I'm sure some try to get away with it).
PR ought to improve, there ought to be more visitors to your site, and the search engines tend to like article sites. I've put in some of my keywords from my articles to Google, and often the article appears high up on the first page.