- Age of web site
- Length of time domain has been registered
- Age of content
- Regularity with which new content is added
- Age of link and reputation of linking site
- Uniqueness of content
- Related terms used in content (the terms the search engine associates as being related to the main content of the page)
- Citations and research sources (indicating the content is of research quality)
- Depth of document in site
- Metrics collected from other sources, such as monitoring how frequently users hit the back button when SERPs send them to a particular page
- Metrics collected from sources like the Google Toolbar, Google AdWords/Adsense programs, etc.
- Rate of removal of incoming links to the site
- Use of sub-domains, use of keywords in sub-domains and volume of content on sub-domains and negative scoring for such activity
- Rate of document addition or change
- IP of hosting service and the number/quality of other sites hosted on that IP
- A common postal address on the “contact us” page
- Hosting uptime
- Broken outgoing links not rectified promptly
- Unsafe or illegal content
- Quality of HTML coding, presence of coding errors
- Actual click through rates observed by the search engines for listings displayed on their SERPs