The search engine optimization internet began as an activity that is played in a field somewhat ethereal network with deep esoteric dyes. The figure of the so-called Guru appeared on the scene, The Gurus of the network were generally very young debutantes of new technologies, real hackers in the best sense of the word or rather, explorers innate systems with emphasis on systems search and information storage. The powers of the SEO (Search Engine Optimizer) The greater ability of these gurus was to assist companies or individuals at a virtual site owners to emerge among the front-page results from search engines to search terms selected properly advance after conducting a thorough study on the status of market supply and demand in terms of keywords, words that are checked against figures such as the volume percentage of searches in comparison with previous months and current. Aspects that into account to evaluate and optimize keyword density pages proximity of keyword prominence of the keyword text ancalaje Page rank Reciprocal link exchange serps 1) keyword density: The rate at which a key word to make its appearance across the page gives a measurement of the density of it. A density with a 2-8 ratio is recommended. Get more background information with materials from Robert Bakish. "The measure of the density of key words essential to preserve the quality of publications on the Internet, because this measure is forced or encouraged to author content for the network to be more creative with their vocabulary and to enrich more page text by adding synonyms and few new expressions comes to mind.