There has been a lot written about the supposed duplicate content penalty and how if your website features duplicate content, you could find your Google rankings disappearing fast.
Rather than go into the whys and wherefores, we will instead look at just what Google is trying to do with its rankings, and by understanding that you should hopefully understand how duplicate content is bad.
Firstly though, what is duplicate content?
Duplicate content is web copy on a page of a website that exists in whole, or in part, on another page on the Internet. That page could exist on the same website, it could be on another website or it could be on multiple websites. You can find out if a page of your website has been copied on (or copied from) another website by using Copyscape and entering the URL of your page. Copyscape will tell you if the content on that page is similar, or exactly the same, as somewhere else on the Internet.
You can also take a sentence from your web copy and search Google for it, placing speech marks either side of the sentence for an exact match. This should show your website, and any websites that feature the same copy.
So why is this bad?
Imagine you’re looking for information on something in Google, and you make a search based on the keywords that you think are most likely to return the results you need. Would you expect to find lots of different pages, all offering relevant information to your search?
Of course you would. But, how useful would it be if you were presented with ten identical results? Once you’ve looked at one, the others are all the same. This would be pretty useless, and if Google offered results like this you would most likely use other search engines instead.
That’s why Google filters results that are duplicate. If your web pages contain text that has been taken from other websites, you will most likely find them filtered in Google, which will affect your rankings, your traffic and your sales.
The real problem is that Google doesn’t always filter out the websites that have done the copying… sometimes the website that first published the content is filtered, especially when a more powerful, more established website has copied the content. This is a common problem for website owners who add their products and listings to more powerful directories in order to increase their sales. They’ll find that the directories are ranking well for searches related to their products, but their own sites are not.
The solution here is to rewrite your product descriptions when you add them to other websites, so that the product descriptions on your website are unique. Without doing this, you could find your rankings suffering badly.