Many article submission websites have universal reprinting terms that cover all articles posted. However, these articles do not hold the copyrights for your original work — you do. When article marketing, it is your responsibility with most article submission websites to post the copyright information for your own work, and to ensure that such rights are protected. Therefore, it is wise to add your copyright information and reprinting terms to the bottom of each article that you submit when article marketing.
Here is an example of the copyright terms that I might add to an article marketing submission for this website: