Image via CrunchBaseGoogle Analytics and doing the Math.

Average Duration is a very important metric to understand about your sites performance metrics. There are lots of ways you can use average duration gain sites into your online visitors.  You can measure visitor engagement between two separate time periods and correlate that to your online marketing activity as an example.

If however the initial assessment is based on faulty data you might just as well compare apples to oranges. Getting the proper measurement of the time your visitor spent on your site gives you a much clearer picture of your customer engagement then just raw page views.

So we know the average visit duration metric from Google is faulty and we certainly don’t have the time to design our own analytic programs.  Rather than throwing out the baby with the bathwater here’s what we can do to get a clearer picture using the data provided by Google Analytics.

Using the pull visits metric provided by Google we can design our own metric easily called absolute visits.  And here’s the math that makes that happen and can provide us with a much clearer picture.

AV is Absolute Visits
TV is Total Visits
BR is Bounce Rate

Calculating absolute visits is just a matter of removing Google’s initial error so we throw out the bounce rate.  So if my total visits is 2000 and the boundary was 25% I have 500 bounces leaving the absolute visits at 1500.  The equation that expresses this is:

AV= TV- (TV*BR)

We can then use this number to calculate real average duration and give it true picture of our site.

RAD is Real Average Duration
AD is Average Duration  (reported by Google)
TV is Total Visits
AV is Absolute Visits

 RAD = (AD*TV)/AV

If you run those calculations back over a sites 90 Day or 12 Month cycle and compare it to the results given by Google Analytics you will be shocked to see how inaccurate Google Analytics computation for AD really is and the degree to which you’ve been mislead by Google. Well maybe you won’t……

PS Don’t hold your breath waiting for Google to do the right thing. After all it is your site not Google’s.

Tags: Analytics, Bounce rate, Google, Google Analytics, Internet marketing, Metrics, Search Engines, Searching