I will try to help out by answering several questions here ("mini" article marketing course).
1.) As mentioned, the "duplicate content penalty" is pretty much a MYTH. You should avoid duplicate content on YOUR OWN website. However, Google doesn't "penalize" you for it. They just ignore it. To prove this point, does anyone out there use a hosted Wordpress blog? (rhetorical question!!!) Do you realize that for each tag and category you assign a post to, that Wordpress creates a separate "page" on your site that contains the same article as your original post. There is also a duplicate of it on your archive pages. So one post on your blog could have at least three (or more) "duplicates" on your site.
*NOTE: Plugins like All-in-one-SEO have a setting to tell Wordpress to not list these pages in the XML Sitemap when it is built. Then Google will not see them.
2.) There is no such thing as "duplicate content" when it is on different websites and you are doing a search. Google will show multiple listings of the same exact article wherever it happens to be found. Try it and see for yourself. Put a phrase from an article that is posted on multiple sites in quotes and do a search on Google. It will list them both (if they are indexed). See items below for info on how to avoid this...
3.) The part of the "duplicate content penalty" that is true is not actually a penalty. It is just the absence of "link juice" that you could have obtained. If Google finds multiples of the same content with links pointing to your site, it will probably give you credit for one of the links and ignore the rest of them.
4.) If you are going to submit the exact same article to multiple sites, submitting to ezinearticles first is probably smart. Technically, it shouldn't matter, as long as the other sites list THE SAME PERSON as the author. Ezinearticles will still allow an article that is posted on other sites as long as it is attributed to the same person (THEY WILL CHECK!).
5.) Assuming that you are using articles to build backlinks (most people are), you should try to get the most bang for you buck and submit your articles to multiple sites.
6.) The best way to do this is with a program/service that does submissions for you. Most of these also provide an "article spinner" that lets you use the same base article and "spin" it into hundreds of unique variations. This can GREATLY increase the value of your articles and lead to many more links that are counted by Google.
Hope all this stuff helps some of you a little. I have listed some programs/services below that can help with your article marketing.
Code:
Free (for a short while) article spinner program - http://thebestspinner.com/
ArticleBot - Spin & submit to 100s of article sites - http://www.incansoft.com/IS0030.php
MyArticleNetwork - Spin & submit to blog network - http://www.myarticlenetwork.com/25021.html
