Google itself has previously clarified the issue at hand: the duplicate content penalty myth is just that – a myth. The search engine giant has earlier released a statement saying there are no penalties for such, or at least not in the way most people mean.
The Webmaster Guidelines were clear: Action is taken whenever an individual republishes and scraped an identical material from another site. This is especially true when that individual clearly has no intent of offering value to his audience, as evidenced by other techniques that he deliberately employs as well – all geared towards manipulating search engine results and ranking. These may include creating domains (or subdomains) and pages which essentially has the same material. Another is by engaging in affiliate programs which offers no originality whatsoever.
On the other hand, the duplication that people often fuss about usually don’t pertain to scraped material, but multiple URLs – which contain the same content - within the same website. While it may affect your overall performance, it is not worthy of penalties.
Another related issue is the republication of one’s own article on different sites. Republication in itself is not punishable by Google. The reason article directories exist is to help authors build a better name for themselves and attain credibility by indicating a backlink to the original source. The problem with this though is that search engines may only choose a single version; the others are filtered.
Search engines are keen on filtering sites that show identical pieces and may consider them spam. Filtering itself is not a form of punishment, but instead an attempt by search engines to provide users a unique and useful reading experience.
As a suggestion, you should:
- Avoid publishing non-original content from other sites which do not provide value to readers.
- If you should engage in any affiliate site, make sure that it gives relevance and value to readers. Whenever publishing syndicated content on other sites, make sure to include a linkback to the original source. This also ensures that the original page obtains a higher ranking than the syndicated one.
- Use Google Webmaster Tools to ensure that your written material is fresh and unique. Through this tool, you would be able to identify duplicates in title tags, as well as gain insights or measures on how you can change these around.
- Should you find another site republishing your article without your permission and with the intention of acknowledging it as their own, file a complaint on Google for possible removal of the article then another on DMCA.