Traditional traffic analysis systems are only able to measure the time elapsed between subsequent clicks on your site. This gives you the time spent on all pages of a visit, EXCEPT for the last page visited. As a result, the total duration of a visit can not be measured. It may be estimated but it is never measured accurately.
Web-Stat has designed a system that allows for precise measurement of that very metric. We do this by pinging the visitor at regular intervals, checking whether he still has your page opened in his browser or not. This gives us an accurate measurement of the time visitors spend on your site. You can then study the level of engagement of your public, over time, per referrer, per entrance page, etc.
This metric is essential to your traffic analysis. Web-Stat is proud to make it available