The quality of the website content is one factor which is determining the ranking of the web page in search engines. In many cases, the content is from the same source, for example many newspapers carry the same report from a news agency, or a press release from a particular business. Search engines consider this content as duplicate content, since the text of these pages is largely similar. It can cause confusion and affect the ranking in search engines, since it is difficult to find out which is the original. Often the website which is better at Search engine optimisation (SEO) may rank well in search engines, though it has copied the content.
Sources of duplicate content
Before discussing the best way to handle duplicate content for SEO purposes, it is important to understand the possible sources of duplicate content. Copying, scraping and duplicating content online, in digital format, is fairly inexpensive unlike offline duplication of content by photocopying or similar methods. Since some SEO firms are experts in manipulating the search engines, they scrape or copy content, which often ranks better than original content. In other cases, many e-commerce websites are selling the same product and they will carry the original specifications from their supplier who may selling through multiple websites.
In other cases, the Web Design and web hosting of the Website could also be the reason why multiple copies of the website exist. While the HTML content will remain the same, there may be multiple versions of the same page with the different prefixes like http://website.com, http://www.website.com and for secure pages https://website.com. To ensure that the search engines are not confused, the webmaster handling the website and SEO should decide which is the original or canonical version of the website, and ensure that all the links go to the original, to avoid confusion in search engines.
Resolving duplicate content issues
One of the most popular methods of dealing with duplicate content is by using 301 redirects of the duplicate pages, to the original page. When a visitor accesses the duplicate content page, the browser will automatically redirect to the original page if the 301 redirect is implemented. This will help to consolidate multiple pages and ensure that they do not compete with each other. In other cases adding the NoIndex, follow tag to the HTML header for each page, can ensure that the duplicate pages are not ranked in the search engines.
In other cases, adding the rel=canonical tag to the duplicate pages, will indicate to the search engines, that the pages are a copy of another page, and it should only include the original page in its index. Instead of ranking the duplicate page, the search engine should only rank the original page in its index, so that its users do not waste their time visiting similar pages. In other cases, when the manufacturer descriptions are used for products being sold, it is advisable for the webmaster to take the effort to rewrite the content, to include additional information, so that it will be differentiated from other websites selling the same products.
Therefore SEO agencies can use different methods to ensure that duplicate content does not adversely affect SEO rankings.