7. User Behavior
Google analyses the amount of time that a user spends on a site after he/she has clicked a link from a search results page. If there is a significant decline in the time spent on the site then it could indicate that the document contains information that is out of date and has become stale. For instance, if after clicking from a Google search results link to a timetable, an average person spent 2 minutes on the site and now the average was under 30 seconds, it would indicate that the timetable was out of date. Google collects this information using the Google toolbar.
Any document that has become stale should easily link through to the fresher version e.g. a product that you no longer sell should link through to the replacement product.
Pages Per Visitor
Another statistic all programs provide is “Page Per Vistor” (PPG). This number tells you how many pages on your website the average visitor checks out while visiting your site. So if your PPG is 1 that means that people are exiting your rite right after seeing your homepage and a good indication that you need to fix your homepage. Depending on the nature of your site the PPG will vary. The higher the PPG, the more interest visitors are taking in your site and the more time they are spending on it. Try to find the “exit” pages that visitors are using the most. This means which one of you webpages most people exit your site from. Knowing and fixing these pages will help you tremendously.
User Maintained/ Generated Data
Google looks at the number of people and the growth in people that add a document to their internet browser's bookmarks/favorites. The basis of this is that people would only add a site to their bookmark/favorites, if the site would be useful in the long term and wanted to visit the site in the future. Google looks at the number of people that then use these bookmarks/favorites to rank a document higher. Conversely, a decline in the number of bookmarks, their usage or deletion of bookmarks could indicate that a document is out-dated and no longer relevant. Google gathers this information from the users of the Google toolbar.