Feeling a bit lost navigating Google Analytics 4 (GA4) for your online shop? You’re not the only one. The move from Universal Analytics (UA) has been a learning curve for many, especially when it comes to finding the key reports to understand your sales and customer behaviour. At its core, GA4 is all about events… every interaction on your site is logged as one. This means you get incredibly flexible and granular tracking of user behaviour, which is a massive plus for online retail/eCommerce. Let’s dive into the essential reports every eCommerce business should be utilising in GA4.

1. Where do your buyers come from?

Knowing how your customers find you is crucial for optimising your marketing spend. GA4 offers two main acquisition reports: “User acquisition” and “Traffic acquisition.”

User acquisition versus traffic acquisition

Both reports are vital for eCommerce. “User acquisition” helps you understand which channels are bringing in brand new customers over time, while “Traffic acquisition” shows the immediate impact of your current campaigns and daily visitor sources for all users, new or returning.

How to find them:

• Head to Reports > Life cycle > Acquisition.
• Choose either “User acquisition” or “Traffic acquisition.”

Key eCommerce metrics to look out for:

• Total Users/New Users: Track your audience growth.
• Engaged Sessions: See how many visits were truly interactive.
• Average Engagement Time: Understand how long visitors are spending on your site.
• Purchase Events: The number of times customers completed a purchase.
• Revenue: Total sales generated by each channel.

2. Sales performance

This is likely where eCommerce businesses will spend most of their time. GA4’s Monetisation reports offer a thorough overview of your product performance, sales funnels, and customer lifetime value.

Overview

The “Monetisation overview” report gives you a high-level summary of your earnings, total buyers, average purchase revenue per user, and various eCommerce events.

How to find it:

• Go to Reports > Monetisation > Overview.

eCommerce purchases

This report is essential for understanding which products are selling, how much revenue they’re generating, and their overall performance.

How to find it:

• Navigate to Reports > Monetisation > eCommerce purchases.

Key eCommerce metrics to look out for:

• Item views: How often products were looked at.
• Add to carts: How frequently items were added to a shopping basket.
• Checkouts: The number of times users began the checkout process.
• Purchases: The final count of successful transactions.
• Item revenue: Sales generated by individual products.
• Product name/ID: Identify your best-selling items.

Promotions

If you run special offers, this report helps you gauge their effectiveness. You can see which promotions led to purchases and revenue.

How to find it:

• Navigate to Reports > Monetisation > Promotions. (Remember, you’ll need to have promotion tracking properly set up in your GA4 implementation).

3. User behaviour

Engagement reports help you understand how users interact with your website beyond just finding you and making purchases. This is crucial for pinpointing areas where you can improve the user experience.

Events

GA4 operates on an event-based model. The “Events” report displays all the events triggered on your site, their frequency, and associated values. For eCommerce, this includes view_item, add_to_cart, begin_checkout, purchase, and any custom events you might have configured.

How to find it:

• Go to Reports > Engagement > Events.

Pages and screens

While GA4 is event-focused, understanding which pages are most popular remains important. This report shows you which product pages, category pages, or content pages are receiving the most views.

How to find it:

• Navigate to Reports > Engagement > Pages and screens.

4. Advanced insights (explorations)

This is where GA4 truly excels for eCommerce businesses seeking more profound insights. Exploration reports allow you to build custom reports and visualise data in powerful ways that standard reports simply can’t.

How to find them:

• Click on Explore in the left-hand navigation.

Funnel exploration: visualising the buying journey

Funnel exploration is incredibly powerful for eCommerce. It allows you to visualise the steps users take on their path to purchase, helping you pinpoint where they drop off and allowing you to optimise your checkout process.

Typical eCommerce journey steps:

1. View Item: User views a product page.
2. Add to Cart: User adds the product to their basket.
3. Begin Checkout: User starts the payment process.
4. Add Shipping Info: User enters delivery details.
5. Add Payment Info: User inputs payment information.
6. Purchase: User successfully completes the transaction.

By setting these steps in a funnel exploration, you can see exactly where users are abandoning the process and then prioritise your optimisation efforts. We have also shown a very simple funnel for eCommerce below to try out.

Path exploration: understanding user flows

Path exploration enables you to see the actual routes users take on your site, both forwards and backwards. This can reveal unexpected user journeys, popular navigation patterns, or even dead ends that cause users to leave your site. For eCommerce, this can help you understand how users browse categories, discover products, and move through your site before making a purchase.

For eCommerce, we recommend hitting “start again” when you enter this exploration at the top right and starting your data with “Purchase” as your end point. This will allow you to explore all the routes your customers take to purchasing on your website.

Note: Clicking on each node will allow you to see steps that follow it.

Organising your data: Custom channel groupings

Inconsistent UTM parameter usage can lead to “unassigned” traffic muddying your GA4 reports. Consistent UTM tagging is absolutely critical for accurate attribution in eCommerce.

Common UTM parameters for eCommerce:

• utm_source: (e.g., google, facebook, email)
• utm_medium: (e.g., cpc, organic, social, email)
• utm_campaign: (e.g., summer_sale_2025, new_product_launch)
• utm_content: (e.g., banner_ad_v2, text_link_blue)
• utm_term: (e.g., mens_t_shirts, running_shoes)

To resolve “unassigned” traffic and create meaningful channel groupings for your eCommerce activities:

1. Standardise your UTMs: Ensure everyone on your marketing team uses a consistent UTM tagging strategy. Numerous UTM builders are available online to assist with this.
2. Create Custom Channel Groupings: This allows you to define how GA4 categorises your traffic based on your UTM parameters.
   • Go to Admin > Data Settings > Channel Groups.
   • Click “Create new channel group.”
   • Define rules based on your UTM parameters. For example (build your own based on what UTMs you use):
     • Paid Social: session_source contains facebook AND session_medium contains cpc or paid.
     • Email Marketing: session_source contains mailchimp AND session_medium contains email.
     • Organic Social: session_source contains instagram AND session_medium contains organic_social.

   This will ensure your traffic is accurately categorised, providing a clearer picture of your channel performance and enabling you to optimise your spending more effectively.

Conclusion

While GA4 is different, it offers powerful capabilities for eCommerce businesses to gain deep insights into their customer journeys and sales performance. By concentrating on the acquisition, monetisation, and engagement reports, and making the most of the flexibility of explorations, you can make data-driven decisions that will significantly impact your online store’s success. Don’t be afraid to experiment with the platform and delve into the data – the insights you uncover will be invaluable for optimising your marketing, enhancing your user experience, and ultimately, driving more sales.