Why tracking has quietly become the biggest lever
For years, conversion tracking was something you set up once and mostly ignored. Third-party cookies did a lot of the quiet work of connecting a click to what happened after it, even imperfectly, and automated bidding was less central to how most accounts were run. Neither of those things is true anymore. Browsers have been steadily restricting third-party cookies, and automated bidding strategies now make constant, granular decisions based on the conversion data an account feeds them. Weak tracking used to mean slightly fuzzy reporting. Now it means the algorithm making your bidding decisions is working with worse information than it should have, every single day.
What's actually changed
Browser level restrictions on third-party cookies have made the old way of stitching together a user's journey, from ad click to conversion, increasingly unreliable. Safari and Firefox have blocked third-party cookies by default for years, and Chrome has moved steadily in the same direction. That matters because standard Google Ads conversion tracking historically leaned on exactly the kind of cookie-based signal that's disappearing.
At the same time, UK and EU consent requirements mean a meaningful share of visitors decline analytics or advertising cookies outright, creating a real, measurable gap in what Google Ads can see, even before any browser restriction comes into play.
Enhanced Conversions, in plain terms
Enhanced Conversions works by securely hashing customer data you already collect, an email address or phone number from a form submission, for example, and sending that alongside the standard conversion signal. Google can then match that hashed data against signed-in Google accounts to confirm a conversion happened, even when a cookie-based signal was blocked or never fired. It's not a workaround or a grey area technique, it's Google's own recommended way of closing the measurement gap left by cookie restrictions, and setup is usually a modest one-off task through Google Tag Manager or the Google Ads tag itself.
Consent Mode, and why it's not optional in the UK
Consent Mode adjusts how Google's tags behave based on the cookie consent a visitor actually gives. If someone declines analytics cookies, Consent Mode allows Google to model an estimate of that missing conversion data based on patterns from users who did consent, rather than losing that visibility completely. For any UK or EU facing business, Consent Mode v2 isn't a nice to have, accounts without it correctly configured are increasingly likely to see reduced conversion visibility and, in some cases, restricted access to certain Google Ads features entirely.
Quick check: Compare your Google Ads conversion count for a recent month against actual enquiries or sales you know happened. If Google Ads is showing meaningfully fewer conversions than you know occurred, that gap is usually a tracking problem, not a performance problem.
First-party data and offline conversions
Beyond Enhanced Conversions and Consent Mode, the broader shift is toward businesses owning more of their own data rather than relying entirely on third-party signals. Server-side or first-party tagging routes tracking through your own domain rather than purely third-party scripts, making it more resilient to browser restrictions. Offline conversion imports let you feed real outcomes back into Google Ads after the fact, useful for any business where the actual sale happens well after the initial enquiry, a quote that becomes a job weeks later, for example, rather than trying to track everything at the point of the click.
What this means for a typical small business account
None of this requires an overhaul of how the business operates, but it does mean conversion tracking deserves more attention than a one-off setup years ago. Worth checking: whether Enhanced Conversions is actually switched on and working, whether Consent Mode v2 is correctly configured rather than just present, and whether conversion numbers in Google Ads roughly match what you know is actually happening in the business. A tracking audit is a relatively small piece of work that directly affects how well every automated bidding strategy in the account performs.
The bottom line
Conversion tracking used to be background infrastructure. With cookies fading and bidding leaning harder on the data it's given, it's now one of the highest leverage things in an account, and one of the easiest to let quietly break without noticing. If performance has drifted and nothing else obviously explains it, tracking is worth checking before anything else.