Whilst checking client stats on Monday I noticed a huge discrepancy between the June and July figures a jump of around 80% in some cases.
Thanks to: Yohay from the things.co blog for his post questioning this issue. As it happens, Bounce rates are now excluded form the Avg. time on site figures and the update was ran on July 20th which accounts for the escalating figures now.
The analytics support team were quoted to have said:
Previously, the Average Time on Site had been calculated as the total time on site for all visits divided by the total number of visits. Both the total time on site and total number of visits included bounces.
As of July 20, 2007, we began reporting the Average Time on Site as the total ti
me on site for all visits (excluding bounces) divided by the total number of visits (excluding bounces). This change also affected data from earlier dates, not just newer data.
Because bounces have been removed from this calculation, you may notice a significant increase in the average amount of time spent on your site. Please be assured that we have in no way changed your data, only the way that the Average Time on Site is being calculated.
This is quite a significant change and I know a few people are wondering why this wasn’t flagged up by Google prior to the update, their is also a question of whether the removal of bounce rates from average time is industry standard. If I hear anymore I’ll update you.