A competitors set up a new site and copy and pasted some copy from our home page.When doing a comparison with a duplicate content tool the result was that the pages where 21% similiar.Does the fact they have copied our content affect our site?Their site has seen an increase in their ranking recently and ours ahs dropped slightly
Does duplicate content on another site affect my ranking?
seo;google;content;ranking
Firstly, if they've copied original content from you without permission this is a breach of copyright, so you could consider legal action. A complaint to their ISP would be the first port of call here. You'd need to be able to prove that you are the original author of the content.Regarding the SEO aspect, from Google's webmaster guidelines:If you find that another site is duplicating your content by scraping (misappropriating and republishing) it, it's unlikely that this will negatively impact your site's ranking in Google search results pages.See also: http://googlewebmastercentral.blogspot.com/2008/09/demystifying-duplicate-content-penalty.htmlGoogle mostly uses 'duplicate content' to avoid including the same content from multiple domains in search results. E.g. if you searched for a book title you wouldn't want to see the same book listing on amazon.com, amazon.co.uk, amazon.fr and amazon.de in the results. In my experience they're pretty good at detecting the difference between this and copied content, and 21% doesn't sound like something that's going to cause you any problems.Remember there are many different factors that affect the ranking of results, so even if you have seen a drop recently I would be wary of thinking that this was the direct result of your competitor's plagiarism.