Search results and user behavior might influence your Google rankings:


the volume of searches over time is recorded and monitored forincreases
the information regarding a web page's rankings are recorded and monitored for changes
the click through rates are monitored for changes in seasonality, fast increases, or other spike traffic
the click through rates are monitored for increase or decrease trends
the click through rates are monitored to find out if stale or fresh web pages are preferred for a search query
the click through rates for web pages for a search term is recorded
the traffic to a web page is recorded and monitored for changes
the user behavior on web pages is monitored and recorded for changes(for example the use of the back button etc.)
the user behavior might also be monitored through bookmarks, cache, favorites, and temporary files
bookmarks and favorites are monitored for both additions and deletions
the overall user behavior for documents is monitored for trend changes
the time a user spends on a web page might be used to indicate the quality and freshness of a web page