What good are articles if they are duplicate content?

Storyman - Good question...

Sure, when someone post one of the articles on their site the links are helpful, but I don't understand what benefit the people posting the articles are getting.

I'm not sure that the links from duplicate articles distributed on article submission sites are that helpful either. I doubt that dupe articles are helpful in conferring link reputation... but that's a long discussion... and my guess is that the quality of the sites that use these articles is low enough that the links also aren't much good for traffic.