Directory Submissions and Article Submissions

Directory Submissions
In this category I’m talking about low quality spammier directories rather than very high quality directories like DMOZ, Yahoo and Yell.com.
Directory submissions are pretty low in terms of relevance and authority but they’re definitely good for link diversity and help to increase the number of IP addresses from which you have backlinks.
I wouldn’t prioritise these links (especially for an already-established website) but they’re always good for a new website as they are something that a typical business owner might look to do when launching their business online so they appear natural.

Article Submissions
Article submissions aren’t a particularly good way of building authority but they’re good at passing relevance to your page as they typically allow you to control both the page content and anchor text. They also normally have a very low number of OBLs so you benefit from all the link juice that the page has to pass.
There are higher authority websites like ezinearticles.com, hubpages, squidoo where you can manually post articles but it’s also possible to use software and web services to automate this procedure.
In the higher quality sites there is stricter moderation and the content you submit should be a better quality.
We personally use Unique Article Wizard which automatically spins (rewrites) the article content and submits it to a number of article directories. While this automated submission only provides low-authority links, we typically see over 100 backlinks being created for each article submitted.
A problem that does exist with article submission is duplicate content. If you were to write an article and submit it to an article directory, a website with higher authority to also
publish the same article which could result in your original article being filtered from Google’s index.
To get around this, you can take articles that are already published on article sites, spin them using spinning software such as “The Best Spinner”, edit the spun article so that it makes sense and has good grammar much more easily that writing fresh content from scratch.
When creating content for use outside of the domain we’re actually trying to rank, we have much looser quality standards and this is a perfect example of when we wouldn’t worry too much. The point of the articles we’re submitting isn’t for them to be read, it’s to create a backlink.