The first component of Google's trust has to do with age. Age is more than a number. But it's not just the age when you first registered your website. The indexed age has to do with two factors: i) the date that Google originally found your website, and; ii) what happened between the time that Google found your website and the present moment in time.
SEO techniques can be classified into two broad categories: techniques that search engine companies recommend as part of good design ("white hat"), and those techniques of which search engines do not approve ("black hat"). The search engines attempt to minimize the effect of the latter, among them spamdexing. Industry commentators have classified these methods, and the practitioners who employ them, as either white hat SEO, or black hat SEO. White hats tend to produce results that last a long time, whereas black hats anticipate that their sites may eventually be banned either temporarily or permanently once the search engines discover what they are doing.