Google indexes article directories periodically because it is easy for the crawlbot to go through the neat categories of the directories. All directories have several categories and sub-categories with hundreds of relevant articles on them. The search engine constantly looks up the new articles in these directories and continues to take notice of the website that they link. If you are consistent in putting up quality articles at top directories, there are good chances of gaining visibility. However, Google would also evaluate the quality of your website. Unless you have a good website, article submission may not be that effective.
Use backlinks with intelligence
It is a well-known fact that Google considers backlinks to your site as positive votes and improves your page rank based on that. However, there are several complex layers. If it was linear, then putting up scores of articles with embedded links would have been a surefire way of gaining rapid visibility. Things so not work linearly always. Google algorithm also does not. In fact, if you are unscrupulous in multiple directory submission at the same time, Google may actually brand you up as spam. To avoid this SEO nightmare, webmasters therefore put up original articles in moderation at groups of top directories at a time. This keeps the pace consistent and comes across to the search engine as an organic signal. Your site directly benefits.
Gaining direct niche visitors
A direct advantage of article submission is the possibility to get direct traffic. Search engines often display directory articles in results to relevant keyword searches. If you have a brilliantly optimized article, information rich and relevant, keep up the high hopes of featuring at the first page. Also, many users bookmark directories for latest updates in their fields. You can effectively reach out to this target audience base through quality submissions. A good article at a quality search engine is a lifetime asset. It would continue to bring in niche visitors for as long as it is worth. Concentrate on developing a quality piece. See that the article presents information in an engaging manner.
Search engine quality parameters are actually quite simple. You have to remember three main aspects: information, engagement, and format. Articles with subheads and bullet points come around as better in presentation than just a dry representation of facts. As long as you are developing/commissioning top quality pieces, your directory submissions strategy should work out fine. However, be moderate with your pace of submissions. Flooding directories with articles, even if they are top quality ones, may not be a good idea. Google prefers organic growth instead of rapid, manipulative rise in references. Another key parameter to remember is to see that the website corroborates with the high standards set by the article. If it fails to deliver in its promises mentioned in the article, the consequences can include severe SEO retribution. A good site with good offsite articles can be a major crowd puller.