Summary
The reports use different attribution models based on their scope. Advertising workspace reports apply the property's reporting attribution model across a lookback window, so Paid Search earns credit for conversions it assisted earlier in the path. Traffic acquisition is session scoped and credits only the source of the converting session, which is why its Paid Search number is lower.
Nitin Batra is a Google Analytics 4 certified analyst who configures attribution settings, audits Advertising workspace reports and reconciles paid channel conversion numbers for client properties.
Last updated: August 16, 2026
- Thresholding is hiding data from the Traffic Acquisition Report.
- The Advertising workspace reports on users, while the Acquisition Report tracks sessions.
- The reports use different attribution models based on their scope.
- The Traffic Acquisition Report is sampled, while the Advertising Report is not.
The correct answer is: The reports use different attribution models based on their scope.
Key Takeaways
- – The discrepancy exists because the reports use different attribution models based on their scope, so Paid Search gets more credit in the Advertising workspace than in Traffic acquisition.
- – Advertising workspace reports apply the property level reporting attribution model, data-driven by default, across a lookback window of up to 90 days for conversion events.
- – The Traffic acquisition report is session scoped and uses Session default channel group with last non-direct click, so credit goes only to the source of the converting session.
- – Changing Admin > Attribution settings to a different model updates Advertising workspace numbers historically, but it will never change the Traffic acquisition report, which is a common source of confusion.
Which attribution model does the Traffic acquisition report use in GA4?
Traffic acquisition uses last non-direct click at session scope. The conversion is credited to the channel that started the session in which the conversion event fired, and direct traffic is ignored if a previous campaign source exists in the session. This is why it never distributes fractional credit the way the Advertising workspace does.
Where do I change the reporting attribution model in GA4?
Go to Admin > Data display > Attribution settings at the property level. There you can choose the reporting attribution model, data-driven or paid and organic last click, and set the acquisition conversion lookback window to 7, 30 or 90 days. The change applies retroactively to Advertising workspace reports.
Is the difference between the two reports caused by data thresholding or sampling?
No. Thresholding hides rows when Google signals demographic data could identify individuals, and sampling only kicks in on large custom explorations. Standard Traffic acquisition and the Advertising workspace reports both run on the same collected data, so the difference here comes from attribution model and scope, not from data suppression.
Which report should I use when reporting paid search performance to a client?
Use the Advertising workspace for media and budget decisions because it credits Paid Search across the full conversion path within the lookback window and matches how Google Ads thinks about assisted conversions. Use Traffic acquisition for on-site behaviour and session level analysis. State clearly in the report which one you used, otherwise the two numbers will be questioned every month.
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