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Is GA4 data sampling affecting your reporting? Here’s how to fix it
Get familiar with Google Analytics 4 data sampling and how to work around it for more accurate reports.
If you’re tracking traffic and marketing channel performance, there’s a good chance you’re using Google Analytics 4 (GA4) to do it.
It’s a popular choice—and for good reason. GA4 lets you see what’s happening on your website in real-time and where your traffic is coming from.
But if you’ve been working with large data sets, you might’ve noticed your reports look a little off.
That’s likely because GA4 sometimes uses data sampling to make things run faster by only analysing part of your data instead of the full set.
In this post, we’ll break down what data sampling is, how it’s different from unsampled data, and share a few tips on how to avoid sampling so your reports stay as accurate as possible.
Here’s what we’ll cover:
💡 Pro Tip
GA4 is built on sampled, aggregated website visitor data and tracks actions like clicks and form submissions, but it doesn’t capture your unique first-party data. It’s not showing you the deeper customer insights from your website touchpoints, conversions, or any CRM data on leads, deals, or revenue. A first party data platform picks up everything GA4 misses. It tracks user interactions with tags that capture UTM codes, click IDs, and conversions (emails, calls, purchases, survey responses). Plus, it integrates ad costs, campaign data, and CRM information, tying everything together to show you how marketing impacts actual business results.
Skip to learn more about first party tracking or book a demo to see it in action.
First, data sampling is a method used to analyse a portion of your data to get useful insights.
Instead of crunching the entire dataset, GA4 sometimes analyses only a sample.
The idea is to get quick, meaningful results without needing every single data point—like polling a smaller group to predict a larger trend.
In GA4, you’ll find two types of reports: Standard Reports and Advanced Reports.
Data sampling typically occurs in the following situations:
GA4 has visual cues to indicate when your data is sampled or unsampled.
A green tick means you’re seeing unsampled, complete data. If you see a yellow percentage icon, GA4 is giving you a sample, and you can hover over the icon to see just how much data you’re actually working with.
While sampling can speed things up by analysing a smaller subset of data, it comes with serious drawbacks for anyone looking to make data-driven decisions.
When you rely on a smaller sample, you’re potentially losing valuable details that a complete dataset would provide.
Less data means GA4 can’t give you the same level of in-depth reporting, making it harder to get the granular insights you need to understand what’s really driving (or hurting) your performance.
You risk making decisions based on partial data, which can impact not only campaign performance but also revenue.
And truth be told, Google Analytics already has its limitations, working mostly with aggregated data.
It’s tracking actions like clicks and form submissions, but it’s not capturing your unique first-party data or giving deeper insights from your website’s touchpoints, conversions, or CRM data on leads, deals, and revenue.
The data you really need to connect marketing to revenue impact is missing.
Stick around, though, because we’ve got a solution to help with that further on.
GA4’s made some progress in reducing sampling, but when you use Advanced reports with high-cardinality dimensions, sampling is pretty much inevitable.
Here are some go-to tricks to help you avoid (or at least reduce) data sampling:
While the methods we’ve discussed are helpful, they don’t address the core limitation of Google Analytics.
As we mentioned earlier, GA4 aggregates visitor data, meaning it lacks detailed, individual-level insights and touchpoints for each visitor.
Plus, it doesn’t capture essential metrics such as revenue, CRM data, or advertising costs
If you can’t track a user’s identity in Google Analytics 4 and what they do after they fill out a form, it’s difficult to know where your highest-value leads are coming from.
And if you can’t include ad cost data, it’s impossible to calculate ROAS for your ad campaigns.
In other words, the link between your marketing, conversions and revenue is effectively broken
A first-party data platform pulls together all your marketing data and ties it to actual business results, capturing everything GA4 can’t.
It brings in all your data, cleans it up, connects the dots, and makes it easy to measure what really matters.
A first-party data platform, like Ruler, starts with a tracking tag that captures sources, UTM codes, click IDs, and logs every conversion down to an individual level like emails from forms, inbound calls, e-commerce purchases—even survey responses.
Ad costs and campaign data are also pulled in so you can see how it lines up with user interactions on your site.
Ruler wraps things up by pulling in data from your CRM—like leads, opportunities, and revenue—and links it back to each visitor’s path on your site.
This helps with data centralisation and connects marketing directly to revenue.
It also integrates easily with various data sources, like marketing warehouses, making it simple to store and process huge amounts of data.
This opens up possibilities for using machine learning and predictive modelling to spot trends and patterns.
Google Analytics has made some improvements to cut down on data sampling, but it’s still an issue.
Plus, it’s dealing with bigger challenges like handling aggregated data and missing details—like individual customer info, CRM data, and ad costs.
This makes it tough for marketers to clearly show how their efforts are driving revenue or to gauge the real profitability of ad campaigns.
That’s where a first-party data platform can make a difference, and a tool like Ruler helps fill in these gaps.
Want to see how it works? Book a demo to see how it provides a more detailed view of your customer journeys and marketing impact.
