Duplicate Content/Mirror Sites: SEO Black Hat Techniques
Search Engine Optimisation: What Not To Do
As well as a source of varied and diverse information, the internet also contains much duplicate, or almost-duplicate, content.
Websites With the Same Copy
If two different websites contain the same written content, many search engines will penalise one, or both, of the websites. Copying text from public domain sites such as Wikipedia and other company, or personal, websites is often done in an attempt to hastily develop site content in the mistaken belief that any content is better than no content. In fact, duplicate content is worse than no content, as both websites will find their ranking in the search engines decrease, and as a consequence, less traffic arriving on their pages.
IP Theft
Many search engines class duplication as trickery - webmasters trying to get quick, free content for their own websites without having to pay for professional copy themselves. Most of the time they are right! And it goes beyond just trickery, as many website content owners would consider the act as intellectual property theft.
Punishment for duplicate content often means that your site is given a new, lower ranking in the SERPS (search engine results pages). The search engines will not usually ban your site completely unless it feels you’re trying to duplicate the entire content of another.
Mirror Sites
Some companies make the mistake of duplicating an entire website on different domains such as .biz, .org, .net, .co.uk, or .com. Google will not be fooled, and will only rank one of these sites at a pretty low level. A mirror site is not a beneficial asset to your online business. Google doesn't want lots of identical content in its results as it hogs storage space and brings frustrating results to readers.
In many instances designers and web masters may not be able to help duplicating certain words or phrases. However, search engines can differentiate between sites with a few similar words or sentences, and the duplicated ones created by web masters for the purpose of affecting their rankings.
Content Filters
Most search engines now utilise a ‘content filter’ whereby they can weed out any websites duplicating content, and only show the user whichever site they decide is the most useful and informative. The danger with this is that if someone has stolen your text, your website could be the one that the search engines decide to blacklist! There is no way of telling who originated the content first of all.
Rather than risk being dropped by the search engines entirely, a web master should be careful not to reproduce text from another source. And website owners should also keep a careful eye on their own content.