The GA4 Reports You Actually Need as a Google Ads Advertiser

The Problem With GA4 Reports

GA4 ships with dozens of reports. Most of them are not useful for a Google Ads advertiser on a day-to-day basis.

The interface is reorganised, labels have changed, and the data behaves differently from Universal Analytics. This creates confusion about where to look and what to trust.

This article cuts through that. Here are the reports that matter, where to find them, and what to look for.

Report 1: Acquisition → Traffic Acquisition

Where: Reports → Acquisition → Traffic Acquisition

What it shows: Sessions broken down by channel group, including Paid Search, Organic Search, Direct, Referral, etc.

Why it matters for Google Ads: This is the first place to check when evaluating whether your Google Ads traffic is performing relative to other channels.

What to look at:

Sessions from Paid Search
Engaged sessions from Paid Search
Key Events (conversions) from Paid Search
Session key event rate for Paid Search vs other channels

Common issue: Google Ads traffic appearing under “Unassigned” or “Direct” - this means auto-tagging is not working or the GCLID is being stripped. Fix auto-tagging in Google Ads settings.

Report 2: Acquisition → User Acquisition

Where: Reports → Acquisition → User Acquisition

What it shows: New users broken down by their first session source/medium.

Why it matters: This shows where your new users are coming from at the user level, not the session level. For Google Ads, this tells you how many new users your paid campaigns are bringing in.

Difference from Traffic Acquisition: Traffic Acquisition uses session-scoped attribution. User Acquisition uses user-scoped attribution (first touch). They will show different numbers for the same channel - that is expected.

Report 3: Engagement → Events

Where: Reports → Engagement → Events

What it shows: All events collected by GA4, sorted by event count.

Why it matters: This is your sanity check for tracking. You can quickly see:

Is purchase firing?
Are custom events arriving?
Are there duplicate event names?
What volume of each event is happening?

If an event you expected is missing or showing zero counts, start debugging here.

Report 4: Engagement → Key Events (formerly Conversions)

Where: Reports → Engagement → Key Events

What it shows: Only the events you have marked as Key Events, with counts per event.

Why it matters: This is a cleaner view of your conversion data without the noise of every auto-collected event. Use it to track conversion volume over time and spot drops quickly.

Tip: Add a date comparison to see week-over-week or month-over-month trends. A sudden drop in Key Events often precedes a performance drop in Google Ads - catching it early helps.

Report 5: Monetisation → Ecommerce Purchases (Ecommerce Only)

Where: Reports → Monetisation → Ecommerce Purchases

What it shows: Revenue, transaction count, items purchased, broken down by item name and category.

Why it matters: For ecommerce advertisers, this shows which products are actually driving revenue. When you combine this with Google Ads campaign data, you can identify which campaigns are driving your best-selling products and which are not.

What to check:

Is revenue tracking matching your actual sales data? (Should be within 5 - 10%)
Are item names and categories populating correctly?
Are transaction IDs unique (no duplicate transactions)?

Report 6: Retention Overview

Where: Reports → Retention

What it shows: User retention rates over the first 42 days after acquisition. Shows how many users return after their first visit.

Why it matters for Google Ads: Poor retention often means you are paying to bring in users who do not come back. If retention from Paid Search is significantly lower than from Organic, your ads may be attracting the wrong audience - or your landing pages are not delivering on the ad’s promise.

Report 7: Explorations - Free Form with Source/Medium Breakdown

Where: Explore → Free Form Exploration

Why it matters: Standard reports in GA4 are limited. When you need to answer specific questions about Google Ads performance, Explorations give you the flexibility to build custom tables.

Useful setup for Google Ads analysis:

Rows: Session source / medium
Columns: Sessions, Engaged sessions, Key events, Engagement rate
Filter: Session source contains “google” AND Session medium = “cpc”

This lets you analyse paid Google traffic in detail, broken down by campaign or source/medium combination.

Report 8: Advertising → Performance

Where: Reports → Advertising → Performance (only visible when Google Ads is linked)

What it shows: Conversion data split by attribution model - Last Click vs Data-Driven.

Why it matters: This report shows how your conversions are distributed differently depending on the attribution model used. If you are evaluating which campaigns are actually contributing to conversions, comparing Last Click and Data-Driven here gives you a more complete picture.

How to Customise the Reports You Use Most

GA4 allows you to save and customise reports in the Library section.

Go to Reports → Library (bottom of the left navigation)
Click Edit collection on your Business collection
Add or remove reports
Drag to reorder

This lets you surface the reports you check daily and hide the ones that are not relevant to your work.

What GA4 Reports Cannot Tell You

GA4 reports are session and event-based. They do not replace Google Ads reporting for campaign-level analysis.

Things that require Google Ads for accurate data:

Impression share
Quality Score
Keyword-level performance
Ad copy testing results
Auction insights

Use GA4 for behavioural analysis (what users do after the click). Use Google Ads for campaign performance analysis (how campaigns are performing in the auction).

They are complementary, not interchangeable.

A Practical Daily Workflow

For a Google Ads advertiser, a useful daily check in GA4:

Key Events report - any unusual drops or spikes in conversion volume?
Traffic Acquisition - any unusual changes in Paid Search session volume?
Ecommerce Purchases (if ecommerce) - revenue and transaction tracking intact?

Weekly:

Retention report - is paid traffic retaining at a reasonable rate?
Free Form Exploration - any patterns in which pages users visit before converting?

This keeps you informed without spending hours in the interface.

Final Thoughts

You do not need to use every GA4 report. You need the right ones, understood deeply.

Traffic Acquisition, Key Events, Ecommerce Purchases, and a well-configured Exploration will answer 80% of the questions that matter for Google Ads performance.

In the next article of this series, we will cover:

GA4 audiences - how to build and export them to Google Ads.

GA4 Explorations - How to Build Custom Reports That Actually Answer Business Questions

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