Interesting query. I've wondered a bit about this myself.

I've found it hasn't made a difference either way for our site, <a href="http://www.beachconnection.net">Oregon Coast Beach Connection</a>.

I get perhaps one hit every few months from any of these syndicated articles.

Now, if it wasn't for the fact we put out a new article every day on this site, I think the article syndication sites might actually hurt us, because of duplicate content being frowned upon by the search engine gods.

A couple years ago, I shot out about 15 articles onto something like 30 syndication sites. I've since abandoned the approach.

As some above have said, use it sparingly, or offer the articles only in teaser form, which then link back to the whole article.

Also, take the time to be picky about which sites you submit to. I submitted a few articles to a handful of high-profile websites that cover specific subjects (like travel in the NW, etc.), and I still get some hits off those every month.

It's nothing compared to our regular traffic-generating concepts, but it works better than just submitting them to sites that shoot your articles out willy nilly.

Then again, you'll also have to be wary of them out ranking you, in which case I would set aside a handful of articles for this that are different or at least fairly different than the ones on your site.