Since Google Panda began in February, 2011, article marketing has changed. Google Panda and its many updates has targeted sites with poor quality content. Most affected were article sites or so-called 'content farms.' Links from sites with low quality content are not valuable links.
The best venues for article marketing are guest blog posts and guest articles on sites relevant to your topic. When Google Penguin rolled out, it targeted low quality links. Here again, the best links are not from article syndication but from high-quality sites related to your site's topic.