Nofollow

Business / Search Engine Optimization (SEO) / Nofollow: Attribute used to prevent a link from passing link authority. Commonly used on sites with user generated content, like in blog comments. Google's Matt Cutts also pushes webmasters to use nofollow on any paid links, but since Google is the world's largest link broker, their advice on how other people should buy or sell links should be taken with a grain of salt. Please note that it is generally not advised to practice link hoarding as that may look quite unnatural. Outbound links may also boost your relevancy scores in some search engines.
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