It takes months for the strategic SEO campaign to produce feasible effect, and in order to achieve fast results many webmasters and Internet marketers use so-called 'black hat' SEO techniques. Search engines continiously battle web spam produced by 'black-hat' SEO - millions of pages created to manipulate search results by spammy linkage, keyword stuffing and other tricks. In my article I describe several statistical methods used by search engine to detect such pages.
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