I have more than 20 blog post on my wordpress blog, promoting clickbank products. Do you think submitting that 20 wordpress blog post into article directories like EZA help to boast my ranking??
No, that would be useless. Write or outsource original articles, and THEN submit to article directories.
plus I think EZA is one of the few article directories that manually reviews each submission.. so if your article looks too spammy or not really adding value then it will not be included.
EZA definitely check your content as oppose to most other directories which usually just use robots to crawl it or something similar. One good technique to use would be to increase traffic for your EZA articles aswell, my EZA articles get 20x the hits my ArticlesBase articles do.
There is nothing wrong in submission of blog posts in article directories. The article you write is a unique one. So post it on your blog first.