Posting the same content in more than 1 location can lead to duplicate content issues. Google "duplicate content" for more info.
What will happen is that the Search Engines will ignore the content with the newer date. So, if you want to monetize your articles, don't copy them as is, but rather change the article a bit, and re-post.
What I plan to do, is if a write a blog post that I feel will have value here, I will write a hub about the article, and link to it.
Hope this helps.