As most people who run their own websites know, one of the basic rules of content is that yours has to be unique. Whether your site is a commercial endeavour in its own right, is intended to promote a business, or even if your site is not run for profit, you want as many relevant visitors as possible, which means doing well on the search engines. Search engines value unique content and dislike duplicates, so when you set about making content, you do what you can to make it original.
But why does duplicate content cause so many problems?
Non-Duplicate Content is Seen As Higher Value
It makes sense to consider that original, unique content would add to the value of the site. It means you are not plagiarising (at least from other web sources), and that means your site is probably higher quality. This all makes sense, and you can see why search engines might have an interest in taking their users to content that is unique and interesting.
Legitimate Reasons for Duplicating External Content
However, there are occasions where this is not the case. You may, for example, want to use the product descriptions for your website that the manufacturer of the products you sell created – both to save the time and money of writing new descriptions just for the sake of uniqueness, and to make sure everything you are saying is in line with the manufacturer’s brand identity. In this case you have a legitimate reason to want to duplicate other content from the web, and more often than not the express permission from the manufacturer to use their copy.
Google, however, still appears to treat this as a duplication, though those skilled in SEO can find ways around this such as having unique category level content and then using ‘canonical’ tags on the duplicate product descriptions for the individual items beneath each category.
Internal duplication of content can be an even bigger problem than having duplications of external content. With external content Google can use other things to determine which page that the content appears on should rank higher in the SERPs, like which site seemed to have published the content first and which has the bigger domain authority, but when the same content appears multiple times within the same site, Google doesn’t know what to do.
Why Would You Have Multiple Pages With the Same Content?
In some cases, you may have used the same content on multiple pages with just a few words changed, for example if you have several products that are essentially the same but in different colours, each with their own page in your catalogue, you may have used the same copy for each page and just changed the colour.
A more troubling reason you may have duplicate content on your site is that your CMS may have generated multiple different URLs for each piece of content you created. To see if this has happened on your site and resolve it if it has, read and follow these instructions on how to get rid of duplicate content.
What to Learn
The fact that uniqueness is so key for SEO is something we mostly have to live with, and in the vast majority of cases original, unique content really will make your site better. In those where you actually have a good reason to be publishing content that exists elsewhere on the web or recycling content throughout your own site, learning about canonicals and other ways of getting the search engines to ignore your duplicate content is important.