It’s been almost a year and a half since Universal Analytics was discontinued, and GA4 has been evolving at speed. In the past 18 months, Google has rolled out more than 45 updates, designed to make the platform more intuitive, insightful and useful for modern marketers.
From new diagnostics that explain data gaps, to expanded audience exports, there’s plenty of untapped value in GA4 right now. In this blog I’ll highlight some of the new features we’ve spotted and tested, and explain how to maximise their value.
Note: The features shared in this blog are based on the Google & Merkle webinar held on 1st July 2025, titled One Year Post-UA: The Ongoing Evolution of Google Analytics.
Data missing or not set:
Here are three diagnostic features you might’ve missed, which will help you take more advantage of GA4’s interface…
Still seeing (not set)? GA4 now flags why
GA4 has introduced a new diagnostic to help you understand (rather than guess) why the dreaded ‘(not set)’ appears in your reports.
Why does this update matter?
‘(not set)’ appears when GA4 can’t capture a value for a specific dimension. That means missing context about traffic sources, page paths or campaigns, and historically, fixing it has involved guesswork or trial and error.
What’s new in GA4?
GA4 now includes a built-in diagnostic that:
- Explains why ‘(not set)’ is appearing
- Links to a help article with specific fixes
- Identifies whether the cause is tagging, configuration, or data availability
How to get the most from this feature
- Check the diagnostic before making any changes
- Share the explanation with developers or your analytics lead
- Prioritise quick-fix items as part of your data cleanup work
Summary
GA4 finally explains why ‘(not set)’ appears and how to fix it, ending the guesswork and helping you maintain accurate reporting.
New Diagnostics for Missing session_start Events
GA4 now alerts you when session_start events fail to trigger, helping prevent undercounted traffic.
Why does this update matter?
If ‘session_start’ doesn’t fire, GA4 cannot log a visit, meaning engagement and conversion data won’t reflect reality. Missing sessions can silently break your reporting.
What’s new in GA4?
GA4 now flags when ‘session_start’ events fail to trigger due to:
- Delayed consent banners
- Fast page redirects
- Single-page apps or embedded consent tools
A diagnostic message explains the likely cause so you can resolve it quickly.
How to get the most from this feature?
Check this diagnostic if:
- Session counts look too low
- You use delayed-consent banners
- Your site uses SPA logic or rapid redirects
Use the flagged causes to guide your fixes.
Summary
This diagnostic helps detect one of the most damaging tracking issues early, ensuring your sessions are counted and your reporting remains reliable.
New Diagnostic Finally Decodes ‘(data not available)’
GA4 now includes a clear diagnostic explaining why ‘(data not available)’ appears, and what to do next.
Why does this update matter?
‘(data not available)’ used to be a dead end, leaving you unsure whether the issue was tracking, permissions, or processing. Now GA4 gives you clarity.
What’s new in GA4?
The updated diagnostic now:
- Explains the likely reason in plain language
- Suggests specific fixes
- Clarifies whether the issue is temporary or requires action
Common causes include:
- Missing permissions
- Report filters excluding all data
- Privacy thresholds suppressing results
- Processing delays
How to get the most from this feature?
Always check this diagnostic before troubleshooting, it can save hours of wasted effort.
Summary
GA4 now tells you exactly why data isn’t appearing, helping you fix issues quickly and avoid unnecessary headaches.
Report display and insights:
Most users are still struggling with the interface, but more recent updates are bringing us closer to the quality of interface we had in Universal Analytics. Two useful updates we’ve found are as follows…
GA4 annotations – finally, some context!
GA4 is reintroducing the long-missed annotations feature, letting you add contextual notes directly to your data timeline.
Why does this update matter?
Without context, traffic spikes and dips are just guesswork. Annotations let you mark key events directly in GA4, making it easier to interpret data months later. For instance, you could annotate the day a newsletter is sent out, helping explain a spike in traffic when you later look back on traffic trends.
What’s new in GA4?
You can now add annotations to note:
- Campaign launches
- Site or platform changes
- Tracking outages
- External events impacting performance
How to get the most from this feature?
- Add annotations weekly to capture notable changes
- We’ve added annotation marks when making significant changes to Google Ads campaigns, e.g. switching conversion goals from phone calls to donations
- We’ve also used it for big events, adding additional data streams, adding product links, reporting identity, and adding data filters like internal IP blocking
- Be specific (e.g. ‘Email appeal launched – 10k send’)
- Encourage your wider marketing and tech teams to use them
Summary
Annotations bring essential context back to GA4, turning confusing spikes into understandable stories.
Generative AI insights – your new data sidekick
GA4 is rolling out generative AI capabilities to automatically surface trends, anomalies, and insights you might otherwise miss.
Why does this update matter?
Sifting through data to spot trends is time-consuming. GA4’s generative insights surface patterns automatically, helping you act faster.
What’s new in GA4?
GA4 can now:
- Suggest possible causes for changes in your data
- Highlight emerging trends
- Flag anomalies that may signal opportunities or issues
These appear directly in the interface as automated insights.
How to get the most from this feature?
- Check the Insights panel weekly
- Use surfaced findings as prompts for deeper exploration
- Remember limitations: AI can’t see the full marketing context
Summary
Generative insights speed up your analysis by surfacing what’s changed, letting you spend more time acting and less time hunting for patterns.
Improved reporting:
Building on the level of accuracy you would’ve received in Universal Analytics, GA4 incorporates more logic and modelling into the way it attributes the sessions recorded on your site…
Ad identifiers retrieval failing? New waterfall logic helps plug the gaps.
Sometimes the special tracking codes that record your ad traffic, like GCLID or DCLID, don’t get recorded (they can break, get blocked, or fail to load).
Now, GA4 has a backup system with multiple layers, meaning that if the main tracking code doesn’t work, GA4 will try other methods to figure out which ad brought the visitor, so your reporting stays as accurate as possible.
Why does this update matter?
Identifiers like GCLID and DCLID tell GA4 exactly which ads drove a user to your site. Without them, campaign attribution becomes patchy, making optimisation and ROI measurement much harder.
What’s new in GA4?
GA4 now uses a waterfall attribution logic when Google Ad identifiers are missing:
- Google Ad Identifiers (preferred) – GCLID/DCLID from autotagging
- Aggregate Identifiers (NEW) – modelled signals used when tracking is restricted
- Manual Tagging – UTMs used as a last resort
This helps preserve attribution completeness even when full identifiers aren’t available.
How to get the most from this feature?
You may already be benefiting if:
- ‘Direct’ or ‘(not set)’ sessions have reduced since mid-2025
- Consent Mode is enabled but campaign data still appears
- Diagnostics reference modelling or aggregated sources
To maximise this feature:
- Enable autotagging
- Maintain consistent UTM tagging
- Ensure Consent Mode is properly configured
Summary
The new waterfall logic keeps your paid attribution intact even when identifiers fail, as long as your tagging and permissions are set up correctly.
Benchmarking: Know if your performance measures up.
GA4 now offers industry-level benchmarks so you can compare your performance against similar organisations.
Why does this update matter?
Benchmarking shows whether your metrics are strong or weak compared with similar organisations, grounding your reporting in a meaningful context.
What’s new in GA4?
You can now benchmark against industry peers on:
- Traffic channels
- Bounce rate
- Engagement rate
GA4 uses anonymised, aggregated industry data to provide comparisons.
How to get the most from this feature?
- Review benchmarks quarterly to understand industry shifts
- Use them to set realistic internal targets
- Bring benchmark data to stakeholder or board reports
Summary
Benchmarking strengthens your reporting, clarifies performance expectations, and helps justify both wins and dips.
Want charity-specific benchmarks? The Charity Digital Benchmark lets you compare performance against similar-sized charities and cause areas, offering insights tailored to charities that GA4 can’t provide.
Partnerships:
One of the best improvements GA4 has made on its predecessor has been its integrations with both Google products and third party applications.
These integrations not only improve the quality of your data within GA4 itself, but improve the data integrity and optimisations within these partner platforms, such as LinkedIn and Meta.
Export audiences beyond Google.
GA4’s new Audience Export API lets you take your audience segments beyond Google Ads and into your wider marketing ecosystem.
Why does this update matter?
Your GA4 audiences are valuable, but historically, they were mostly locked inside Google Ads. Unlocking them means better personalisation and better campaign performance across all channels.
What’s new in GA4?
With the Audience Export API, you can now:
- Build an audience in GA4
- Send it to your CRM, ESP, or social ads platforms
- Activate users beyond Google’s ecosystem
How to get the most from this feature?
- Sync audiences with your email platform for re-engagement
- Push high-intent segments to paid social
- Connect audiences to your CRM for personalised journeys
Summary
Your GA4 audiences are now cross-channel assets, enabling more targeted, impactful marketing wherever supporters are active.
Final thoughts...
GA4 has come a long way in just a year and the updates we’ve covered here demonstrate Google is listening to user pain points.
To get the most from these features, make sure your tagging is solid, your Consent Mode is correctly configured, and your team knows how and when to use the tools.
Now is the perfect time to:
- Review your diagnostics
- Audit your tracking
- Start using annotations and benchmarking
- Explore audience activation beyond Google
GA4 will keep evolving, the question is whether charities are prepared to take advantage of it. If you’re curious what steps your charity can take today to refine your analytics and GA4 setup, get in touch! Our crack team of digital analysts are always happy to chat.
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