This is my curious. If I produced (or hire someone to do) original and useful article then submit them to many article directories. Will all of them counted as backlink? Refer to Google content duplication issue. I wonder if the same content have been posted to many article sites, would they be duplicated among themselves? Do article marketing still help in backlink and ranking?
Sxperm, If G really penalized you like shet for duped content - DP would have been penalized a gazillion times. Usually when you do article marketing, its OKAY to have one article for a set of submits - and not over-do or over-spam one article to a gazillion directories. The effect of spamming one article onto many directories will be that the link juice you are getting will be devalued and it wont affect your current ranking in any way.