Еще о Google PR

Еще одна формула:

GoogScore = (KW Usage Score * 0.3) + (Domain Strength * 0.25) + (Inbound Link Score * 0.25) + (User Data * 0.1) + (Content Quality Score * 0.1) + (Manual Boosts) - (Automated & Manual Penalties)

KW Usage Factors:

* KW in title tag
* KW in header tags
* KW in document text
* KW in internal links pointing to the page
* KW in domain and/or URL

Domain Strength

* Registration history
* Domain age
* Strength of links pointing to the domain
* Topical neighborhood of domain based on inlinks & outlinks
* Historical use & links pattern to domain

Inbound Link Score

* Age of links
* Quality of domains sending links
* Quality of pages sending links
* Anchor text of links
* Link quantity/weight metric (Pagerank or a variation)
* Subject matter of linking pages/sites

User Data

* Historical CTR to page in SERPs
* Time users spend on page
* Search requests for URL/domain
* Historical visits/use of URL/domain by users GG can monitor (toolbar, wifi, analytics, etc.)

Content Quality Score

* Potentially given by hand for popular queries/pages
* Provided by Google raters (remember Henk?)
* Machine-algos for rating text quality/readability/etc


отсюда. Еще и довольно интересная дискуссия. Еще по теме см. здесь.