So I guess if I write articles and put them on my site I shouldn't submit them to any article directories. That makes sense. But what about duplicate content between sites I own such as:
http://www.qualitytrafficsupply.com/guarantee.php
and
http://www.qualitypopunders.com/guarantee.php
That's generally the exact same content. I assume that it would only hurt me for people searching for "website traffic guarantee" and not the rest of my website. Would it be in my best interest to make sure there is no duplicate content anywhere in any of my sites?