Articles in the directories will be indexed in the search engines on their own page, with your link at the end. So 5,000 pages with your article increases your chances of a search engine user locating it, reading it, and visiting your site afterwards. Why? They want more info or have come to the conclusion that you know what you are talking about, if it is a very informative article. While these pages move up in the SERP’s over time the page they are linked to will move up also. For Search Engine purposes, the backlink that follows the article should not have the article on it. Why? Search engines like unique content and the visitor doesn’t want to read the same article over. They want more relevant info that wasn’t included in the article.