Tag Archives: Session Timeout

When Does a Google Analytics Session Expire, Really?

One of the many ways that Google Analytics and Adobe Analytics differ are their individual definitions of what constitutes a session. Both abide by the industry standard of a session ending after 30 minutes of inactivity*.

* Unless you’ve changed the session timeout setting in a Google Analytics property, or the visit definition/visit timeout setting in an Adobe Analytics virtual report suite.

But Google Analytics has an additional trigger for ending a session that can be a real gotcha when trying to matchback data across the two tools: it ends a session and starts a new one “every time a user’s campaign source changes.” That statement always perplexes me because I’m not sure whether to interpret that as:

  1. when any UTM parameter changes, or …
  2. when only the utm_campaign parameter changes

I always assumed #1, but I decided to test this out so I’d be 100% sure. In each test scenario below, I opened a new guest browser window so none of my activity from each test would overlap.

If all other UTM parameters are the same but utm_medium is different, it will start a new session.

The proof: I loaded two URLs with identical values for utm_source, utm_campaign, and utm_id, but different values for utm_medium.

kotaraindustries.com?utm_medium=affiliate&utm_source=halee.com&utm_campaign=201810101234&utm_id=201810101234
kotaraindustries.com?utm_medium=partner&utm_source=halee.com&utm_campaign=201810101234&utm_id=201810101234

When I pull up the report by one of the other parameters, it shows two sessions, validating that a new session was started when I loaded that second page.

If all other UTM parameters are the same but utm_source is different, it will start a new session.

The proof: In a new, fresh guest window, I loaded two URLs with identical values for utm_medium, utm_campaign, and utm_id, but different values for utm_source.

kotaraindustries.com?utm_medium=affiliate&utm_source=benicetobears.com&utm_campaign=201810101232&utm_id=201810101232
kotaraindustries.com?utm_medium=affiliate&utm_source=benicetootters.com&utm_campaign=201810101232&utm_id=201810101232

Again, two sessions:

If all other UTM parameters are the same but utm_campaign is different, it will start a new session.

The proof: In a newer, fresher guest window, I loaded two URLs with identical values for utm_medium, utm_source, and utm_id, but different values for utm_campaign.

kotaraindustries.com?utm_medium=affiliate&utm_source=nxt.com&utm_campaign=201810101230&utm_id=201810101230
kotaraindustries.com?utm_medium=affiliate&utm_source=nxt.com&utm_campaign=201810101231&utm_id=201810101230

How many sessions? Two sessions!

If all other UTM parameters are the same but utm_content is different, it will start a new session.

The proof: In the newest, freshest of guest windows, I loaded two URLs with identical values for utm_medium, utm_source, and utm_campaign, but different values for utm_content.

kotaraindustries.com?utm_medium=affiliate&utm_source=halee.com&utm_campaign=201810101235&utm_id=201810101235&utm_content=version-a
kotaraindustries.com?utm_medium=affiliate&utm_source=halee.com&utm_campaign=201810101235&utm_id=201810101235&utm_content=version-b

Two sessions:

If all other UTM parameters are the same but utm_term is different, it will start a new session.

The proof: I loaded two URLs (in yet another guest window) with identical values for utm_medium, utm_source, and utm_campaign, but different values for utm_term.

kotaraindustries.com?utm_medium=affiliate&utm_source=halee.com&utm_campaign=201810101237&utm_id=201810101237&utm_term=keyword-1
kotaraindustries.com?utm_medium=affiliate&utm_source=halee.com&utm_campaign=201810101237&utm_id=201810101237&utm_term=keyword-2

This is getting boring and predictable, two sessions:

If all other UTM parameters are the same but utm_id is different, it will start a new session.

The proof: Another test, another guest window. I loaded two URLs with identical values for utm_medium, utm_source, and utm_campaign, but different values for the elusive and not-often-used utm_id.

kotaraindustries.com?utm_medium=affiliate&utm_source=wwe.com&utm_campaign=201810101228&utm_id=201810101228
kotaraindustries.com?utm_medium=affiliate&utm_source=wwe.com&utm_campaign=201810101228&utm_id=201810101229

Dos sessiones:

So there you go. Irrefutable evidence that a new session starts on change of any of the following:

  • utm_medium
  • utm_source
  • utm_campaign
  • utm_content
  • utm_term
  • utm_id