GA4 has two acquisition reports that look similar but answer different questions. If a team mixes them up, channel performance reports, stakeholder dashboards, and ROI discussions start from the wrong definition.
User acquisition vs traffic acquisition
GA4 has two acquisition reports that are frequently confused:User AcquisitionandTraffic Acquisition. They look similar, they both show source/medium breakdowns, but they answer fundamentally different questions and use different attribution logic — much like the broader change fromUniversal Analytics to GA4redefined sessions and metrics.
User Acquisition asks:where did this user come from when they first ever visited the site?Traffic Acquisition asks:where did this session come from?For a user who first arrived via paid search and later returns organically, User Acquisition credits paid search; Traffic Acquisition credits organic for the return session. The split reflects the broader logic inGA4 attribution models, where user-scoped and session-scoped dimensions follow different rules.
Cohort analysis and retention
Beyond the two acquisition reports, GA4'sCohort Explorationlets you track how well each acquisition cohort retains over time. A cohort is a group of users who first visited your site in the same time period. Retention measures what share of that cohort returns in subsequent periods — and pairs naturally withengagement rateas a quality signal.
This is where the User Acquisition report's user-scoped logic becomes strategically useful: you can define a cohort as "users first acquired via Paid Search in week 1" and compare their 4-week retention against "users first acquired via Organic Search in week 1." This reveals which channels acquire users who actually stay and engage, not just users who arrive and leave. Counting that retention correctly depends on a clear understanding ofhow GA4 counts sessions.
Decide what question you are answering
Before opening a report, be explicit: are you measuring new user acquisition (go to User Acquisition) or overall session performance (go to Traffic Acquisition)? Document this in your reporting template so stakeholders interpret the data correctly.
Use the correct dimension for each report
In User Acquisition, use First user source / medium. In Traffic Acquisition, use Session source / medium. Using Session dimensions in User Acquisition or vice versa produces misleading data.
Set up cohort exploration for retention analysis
Go to Explore > Cohort Exploration. Set the cohort inclusion condition to First touch, the cohort granularity to Weekly, and the metric to User retention rate. This shows you the percentage of each week's new users returning in weeks 1 to 4.
Segment cohorts by acquisition channel
Add First user medium as a segment breakdown in the Cohort Exploration. Compare retention curves across organic, paid, email, and referral. Channels with high acquisition volume but low week-2 retention may be bringing low-quality traffic.
Connect retention to business outcomes
Add purchase or key-event metrics to the cohort view if you want to compare which acquisition sources bring users who later return and convert.
Acquisition report audit plan
Validate
- Confirm team reporting templates use the correct report (User vs Traffic Acquisition) for each use case
- Check that User Acquisition report uses First user dimensions, not Session dimensions
- Verify Traffic Acquisition report uses Session source / medium as primary dimension
- Confirm Cohort Exploration is set up with weekly granularity and correct inclusion event
- Check that paid campaign UTMs are consistent enough to allow meaningful cohort comparison
Fix
- Update any existing dashboards mixing User Acquisition and Traffic Acquisition dimensions
- Document which report to use for which business question in your analytics style guide
- Rebuild cohort reports that used incorrect dimensions, the data in GA4 is still correct, only the reporting setup needs fixing
- Align UTM naming conventions so channel-level cohort comparisons are meaningful
Watch for
- Stakeholders comparing numbers from User Acquisition and Traffic Acquisition as if they measure the same thing
- Paid channel ROI calculations using Traffic Acquisition data (inflated by returning user sessions)
- Cohort retention dropping sharply in week 2 for a specific channel, may indicate ad creative or landing page mismatch
Acquisition reporting checklist
- User Acquisition report uses First user source / medium dimension
- Traffic Acquisition report uses Session source / medium dimension
- The report choice is documented against the business question instead of used interchangeably
- Cohort Exploration set up with weekly granularity and retention metric
- Retention benchmarks established per acquisition channel
- Reporting documentation clarifies User vs Traffic Acquisition use cases
Related guides to read next
GA4 Attribution Models Explained
Understand how first-touch, last-touch, and data-driven attribution interact with acquisition reporting.
GA4 Dimensions and Metrics in 2026
Reference guide for all GA4 dimensions including First user vs Session user variants.
GA4 Custom Events Audit
Ensure your conversion events are correctly configured before building cohort analysis on them.
Review your GA4 acquisition reporting
GA4 Audits helps teams check acquisition-report usage, traffic-source dimensions, and attribution hygiene before dashboards harden the wrong interpretation.