Just another thought on article directories: I logged into Ezine Articles and saw that my articles had now been viewed over 3000 times. This level of exposure is several times greater than any of the other major directories I submit to. The site just gets monster traffic.
Then there is the SEO benefit that I've observed. Of course it's hard to tell which directories work best for this, but there always seems to be improvement in the rankings some time after I've submitted to Ezine Articles.