Accurate session duration tracking with Google Analytics
The default Avg. Session Duration metric in GA is not what you would expect. Simply put, it disregards the last pageview for every session, and as a result disregards all sessions with only one pageview.
As a work-around you can send interactive events periodically, telling GA that the session is still active on the current page, which will update both Avg. Session Duration and other time metrics such as Avg. Time on Page.
The events have to be interactive, which is the default. However, that will destroy the Bounce Rate metric instead, so we’ll have to do this on a separate GA profile to keep it non-destructive.
You might also limit this to a percentage of sessions, or send pings less often, or send pings using a smarter algorithm, to keep it from bumping up against the GA account limits.
