My post on exactly how Time on Page and Time on Site are calculated by Web Analytics tools was well received but there were some people who had this reaction:        “Good lord! This seems so fragile! Abandon ship!!” I was not totally surprised at the reaction because people deep in the trenches (and I don’t like to think of myself as one of those but sadly I do spend a lot of time there) realize that a lot of Web Analytics data collection is fragile. It is partly the nature of the web, partly how we collect…