I've found it is all in the quality of what you submit.

I was introduced to Ezine Article Submission - Submit Your Best Quality Original Articles For Massive Exposure, Ezine Publishers Get 25 Free Article Reprints about a year ago and began using it to promote a niche stock market simulator game site I had built.

The quality of the articles directly relates to the links you get back. By writing intelligent articles on television and stock market games I found a lot of links flowing back to the game site within a matter of a few weeks.

Another good site is Helium - Where Knowledge Rules - where you can write articles that get peer reviewed and rated by other helium members, plus the page views your articles get can generate small amounts of revenue for you or whoever is submitting articles on your behalf.

Being that I am working as a bootstrap operation - I do not use paid submissions for article writing, so I cannot comment on that method. I would imagine that it is pretty much the same though - it's all in the article itself, not the directory. A good article will get noticed and will get you cross-links - a poor article will flounder.