Search engines avoid offering their users duplicate content because diversity helps to improve search quality, an expert has remarked.

Eric Enge, president of Stone Temple Consulting, made his comments in a post for Search Engine Land, noting that portals will usually only offer up one copy of an article.

"If a user clicks on one search result and sees a given article but it is not what they are looking for [then] the search engine is not helping them by showing more copies of the same content," he continued.

Furthermore, the search engines compare content when ranking articles, meaning that it is not just direct duplications but overly-similar information which can be discarded, Mr Enge added.

Earlier this year, E-consultancy commented that producing unique content is the "golden rule" for those trying to boost their search engine ranking.

It remarked that websites which fill their pages with sentences and articles used elsewhere risk being penalised by search engines such as Google.