Pagerank, that object of desire after which all the Webmasters runs, with the illusion to increase it, is simply a complex mathematical calculation, used by Google to calculate the popularity of the Web sites. That is to say, the index, has looked for most objective possible, to know which site is more important, and to be able to grant some more or less logical hierarchy to him, to the ordering of the 3,000 million Internet sites that there is in the Network of Networks. In order to calculate pagerank, incoming Link is taken to each as a species of vote that the other sites of Internet do to that page. That is to say, whichever greater amount of incoming links has a site, higher his pagerank. Also they influence in pagerank the quality of links that goes to our site. Meaning that the more high he is pagerank of the sites that linkean to us, the more favorable it will be for our own pagerank. Thus, a single connection of quality can make a difference, as soon as improvements in our numbers significant. All the links are not considered by Google. In first term, those links that are preceded by the attribute, do not count at the time of elaborating pagerank. This responds to a effort to control the Spam, and the little ethical ways that exist to try to influence in this index. This way, it does not agree to include in our site I connect towards penalized sites (whose pagerank is of zero) nor towards which farms of links are denominated , fraudulent created sites to generate incoming links. The sites that connect to us, cannot damage to us, but the sites to which we connected, if. But, why it serves really pagerank? When the lists are armed of natural results, that arise when somebody makes a consultation in Google, the seeking take into account two great groups of factors: the inherent ones to the page, controlable by the Webmaster. For example, the textual content of the page, tags that includes in the source code of the site, etc. and, the other great group of factors, is external elements to the page, like incoming links, and pagerank. Then, if we sell properties in Ibiza, and the consultation of a user is that in particular, we want to above go out listings good in the natural results. It is a fact of the life that does not serve to leave listing beyond page two, because the sites that leave well high in the list of natural results, since the possibility that is higher that lead (possible client) ends up closing its purchase with the first sites that sees listings.