On Thursday Google made a change to how Google Analytics will calculate new visitor sessions. Here is the important change below, notice the nuance.
What’s changing?
Currently, Google Analytics ends a session when:
- More than 30 minutes have elapsed between pageviews for a single visitor.
- At the end of a day.
- When a visitor closes their browser.
If any of these events occur, then the next pageview from the visitor will start a new session. In the new model, Google Analytics will end a session when:
- More than 30 minutes have elapsed between pageviews for a single visitor.
- At the end of a day.
- When any traffic source value for the user changes. Traffic source information includes: utm_source, utm_medium, utm_term, utm_content, utm_id,
utm_campaign, and gclid.
As before, if any of these events occur, then the next pageview from the user will be the start of a new session.
What does this mean for your web analytics trends?
After Aug 11, sessions will be measured will change, and previous session statistics will remain the same. The real change here is measuring a new session when a visitor’s campaign information changes.
Meaning that when you click on a newsletter link with a campaign link including (utm_source=newsletter) and then click on a banner ad including a campaign link (utm_source=ppc) your session will start tracking based on the source of the banner ad for the pay-per-click campaign.
However the side effect of this change could be that he number of visitors being reported in your web analytics tool could increase. Google is expecting to see less than 1% change based on their own research.
