Welcome to the big signal loss
Signal Loss is what happens when the evidence gets thinner while the demand for it stays the same.
The 2026 edition of the CMO Survey, a US-based survey of, in this instance, just over 300 CMOs, posed the question: What actions do you take to show the value of marketing to other functions?
Of the 248 who answered that question, 86.3% (the most common answer) responded with ‘develop stronger marketing performance tracking’.
The industry’s answer to “prove it” is “track it better”, but, as I’m going to argue here, better tracking is further from reach than it has been at any time since the web went mainstream.
Why signal loss matters now
As we move into Q4, the stakes get higher. Q4 is when reviews begin; teams will be looking back over the year-to-date, they’ll be looking at how close to target they are, what corrections may be required to close the gap, and what can be learned.
This moves into planning for the year ahead. With 2027 only one quarter away, teams will be using data to make decisions about where to focus next.
Finally, it's time to prepare board and regulatory reports.
All of these rely upon solid foundations, and those foundations are built on reliable data.
Examples of signal loss
In 2026, marketers, operations teams, and the board have less access to reliable data than they did even a few years ago.
Firstly, thanks to crackdowns on data collection, tools like Google Analytics are effectively now an opt-in resource. If you follow the letter of the law, collecting web analytics data via GA4 needs your audience to explicitly accept that.
It’s one of the reasons why the web is littered with ‘cookie banners’. The banners ask whether you accept the terms on offer or not. The brands that follow the rules essentially see GA4 go dark.
The Data (Use and Access) Act relaxed the rules for analytics cookies from February 2026, but only for tools that collect aggregate data and don't share it onward. Standard GA4 doesn't meet that bar out of the box, and the configuration changes needed to get it there are contested enough that compliance teams in financial services are likely to keep the consent banner.
According to Clickport, some 20-30% of your analytics data will go missing when you implement the correct compliance mechanism. In my experience, the reality is much higher; we’ve seen sites lose up to 80% of traffic visibility when adopting a compliant policy.
Then there’s the challenge of privacy-conscious browsers. Safari, Firefox, and a raft of other browsers operate a policy of rejecting various cookies and tracking tools. This is relevant: Google’s Chrome retains its market leader status in the browser market, but Safari has almost 50% of the mobile market in the UK sewn up.
Even when your customer opts into analytics tracking, you may not be getting a representative sample. Let’s say 50% of your audience opts in; that might be a skewed audience that is over-representative of one segment and not another.
It’s not just web analytics that has wobbly data, either. There’s the data you can’t see:
In August 2026, Google launched passthrough redirects from its search results, a change that makes third-party rank tracking harder
As more people use generative AI tools for information retrieval, they are less likely to click through to your website
Even when they do click through, it’s hard to know where they clicked from
And then there’s the data you can’t trust:
Privacy-led browsers won’t retain cookies as long, so even when you track a user, they’ll only stay in scope for a short time, meaning your ‘new visitor’ number will be inflated
Bot traffic to your site will skew the overall picture
Ad fraud is a thing; if you run ads, some of the results may be from fraudulent sources
We’re only scratching the surface here, but the overall message is this: the data you used to rely upon to make decisions is getting less reliable.
Triangulation is the answer
So what is a brand to do? The answer is to stop relying on any one source.
Data triangulation is the method for doing this. When you need to make a decision on something, don’t use a single source (GA4, for instance), but combine it with data from elsewhere (Google Search Console and Ahrefs, for instance).
The power of triangulation is that you get a stronger signal and you accept and work around the flaws of individual platforms.
Say, for example, that GA4 shows organic traffic is down by 40% year on year. Search Console shows clicks are flat, and Ahrefs shows rankings are holding. Taken on its own, the GA4 data say you've got an SEO problem. Reviewed together, though, the sources say your audience isn’t accepting tracking. They are two very different conclusions to draw and would meaningfully change the strategy you prepare.
At the start, I said 86% of CMOs see stronger performance tracking as the way to prove marketing's value. That tracking isn't coming, so the job now is to make better judgements with what we have.