Search code examples
google-analyticsweb-analytics

Different Active Users count when using segments

I would love to understand what I'm looking at - why are the numbers different in this report when I add a segment?

This is the report without any segmentation:

Without Segments

This is the same report with the Mobile Traffic segment:

With Segments

Solution

  • You are victim of sampling: https://support.google.com/analytics/answer/2637192?hl=en

    Sampling applies when:

    • you customize the reports
    • the number of sessions for the report time range exceeds 500K (GA) or 100M (GA 360)

    The consequence is that:

    • the report will be based on a subset of the data (the % depends on the total number of sessions)
    • therefore your report data won't be as accurate as usual

    What you can do to reduce sampling:

    • increase sample size in UI (will only decrease sampling to a certain extend, but in most cases won't completely remove sampling)
    • reduce time range
    • create filtered views so your reports contain the data you need and you don't have to customize them