Conversion tracking is the foundation that everything else in Google Ads depends on. Without it, Smart Bidding has no signal to optimise towards, budget decisions are guesswork, and there is no way to know whether the money being spent is generating anything of value. Yet when I audit accounts, missing or misconfigured conversion tracking is one of the most common problems I find, and it's almost always the primary reason the account isn't performing.
A common misconception I come across: business owners assume that because they're getting enquiries, their tracking must be working. The two things aren't connected. I audited a plumbing company in North Wales last year who were getting leads, had been running ads for eight months, and had zero conversion data in their account. Every optimisation decision their previous manager had made was based on clicks alone.
The less obvious point: broken tracking is often more dangerous than no tracking, because it creates false confidence. An account showing 40 conversions a month that are actually all duplicate firings from a mis-tagged thank-you page will be optimised in completely the wrong direction.
Here are the five specific things that go wrong when conversion tracking isn't in place.
1. Smart Bidding becomes a liability
Google's automated bidding strategies, Maximise Conversions, Target CPA, and Target ROAS, are built on conversion data. They work by identifying patterns: which searches, times of day, devices, and audience segments produce conversions, and adjusting bids accordingly. Without conversion data, these patterns don't exist.
What happens in practice: Smart Bidding defaults to maximising clicks rather than outcomes. It bids on whatever is cheap enough to stay within budget, not on whatever is most likely to convert. The result is often high spend with low returns. The algorithm is doing exactly what it's told, but without the data it needs to do it usefully.
Target CPA without conversion data is particularly dangerous: the algorithm sets bids based on a target it has no basis for calibrating, leading to either severe underspending (it won't bid where it can't calculate the target will be met) or volatile spending trying to find a conversion signal that isn't there.
2. You can't see what's working
Every Google Ads account has campaigns, ad groups, keywords, ads, and audiences. Some of these generate customers. Some consume budget without generating anything. Without conversion tracking, you cannot tell which is which.
The default Google Ads interface reports clicks and impressions. These tell you the ad is showing and getting clicked, but they tell you nothing about whether those clicks are becoming customers. Optimising towards clicks produces more clicks. It does not produce more customers.
When I take over an account without conversion tracking, the pattern is predictable: budget is distributed roughly evenly across everything, including the keyword and ad combinations that have never generated a lead. The accounts with the highest wasted spend are almost always the ones without tracking.
3. Budget decisions have no basis
How do you decide whether to increase or decrease spend on a campaign without knowing what it's returning? Most businesses with untracked accounts either spend a fixed amount indefinitely regardless of results, or make decisions based on qualitative gut feel ("we've been getting more enquiries lately"). Neither is reliable.
Conversion data gives you a cost per acquisition, the figure that tells you whether spending more makes commercial sense. If your CPA is £50 and you're operating with a healthy margin, increasing budget is the obvious decision. If your CPA is £400 on a product with a £200 margin, something needs to change before you spend more. Without the CPA figure, you cannot make this assessment.
4. Misattribution skews everything
Without proper conversion tracking, businesses often fall back on proxy measures: phone calls not connected to Google Ads, website enquiries not attributed to any traffic source, or sales tracked by a different system with no integration to the ad account. The result is that Google Ads' actual contribution to the business, positive or negative, remains unclear.
Some businesses end up running campaigns for months that are generating few to no customers, but continue because nobody can definitively prove the campaigns aren't working. Others pause campaigns that are actually contributing, because the contribution is invisible in their data.
5. Optimisation is impossible without a feedback loop
Good Google Ads management is an iterative process: make changes, measure outcomes, refine. Without conversion data, this loop breaks. You can change bids, ad copy, and targeting, but you have no way to know whether those changes made things better or worse.
I audited an account recently where the previous manager had been making weekly optimisation changes for six months, cycling through different bids, different audiences, and different ad copy, all without conversion tracking in place. From a data perspective, every change was made in a vacuum. The account had accumulated six months of "optimisation" that was effectively random, because there was no feedback mechanism to indicate whether any of it was working.
How to set up conversion tracking
The most reliable approach for most businesses: set up Google Ads conversion tracking for form submissions using the "Page URL" method to track thank-you page visits, or via Google Tag Manager for more precise event-based tracking. Set up call tracking using Google Ads forwarding numbers for phone calls from ads. If you're already using Google Analytics 4 with proper event configuration, import GA4 goals into Google Ads.
Check that tracking is firing correctly using the Google Ads tag diagnostics tool or Tag Assistant. Verify that conversions are appearing in the Conversions column within 24 to 48 hours of real enquiries.
Once tracking is confirmed, every campaign decision, including bidding strategy, budget allocation, and keyword changes, should be evaluated against conversion outcomes, not clicks. When I audit accounts for North Wales businesses, missing or broken conversion tracking is the single most common finding, and it's almost always the reason results have felt disappointing. For a full picture of what else gets checked beyond tracking, here's what a Google Ads audit covers.
Once you have conversion tracking in place, the next step is reading the data intelligently. Read Google Analytics 4 Conversion Reports: A Practical Guide for a full walkthrough of where the reports live and how to act on what they show.
Google Ads management in North Wales: if you'd like help setting up conversion tracking or an audit to check whether your existing tracking is working correctly, get in touch.
