Currently, authority, or as it is called, the trust domain, quite a profound effect on the ratio of the search engines to the site as a whole. Of what is Trust sites in terms of search engine? Each search system has a number of criteria for Trust sites, and each search engine, or that criterion will have a different weight, but, in general, all the search engines, this set is about the same. One of the important criteria assess the site search engine, is the story of the domain. She talks about what sites were located on this domain before, how long they have existed if it was a site for the entire period from the start, broke a sites on this domain, the rules for participation in the search engines and so on. Another important factor is how often people ask this in the search domain. About the role of quality links to other trust resources say I do not think worth it, because that's obvious. Obviously, if the site has a link to the Trust sites, the search engine this site will be more attractive than a site that does not have such links.
Similarly, outgoing and have a value link to this site, that is, the important trust resources that are referenced in this site domain, but this factor is less important than the first and second. In general, if you want to favorably look in the eyes of search engines, it is not neglect these rules, work on site, observing all the rules that specify how the search engines criteria that determine the quality of the site. The credibility is earned over time and the development of the site. If you want to accelerate this process – get the trust of a site with the resources that searchers have found it credible. It is not necessary to resort to questionable methods of gray and black advancement, if you do not want to get into disfavor search engine to your site.