Why measurement has to be finished before the campaign starts
A campaign on broken tracking is an expensive experiment in the dark. The three mistakes we see most often, and how to spot them before they cost money.
The most expensive mistake in performance marketing costs nothing to make. It happens the moment a campaign launches on tracking nobody verified — and three months later the numbers in the report turn out to correspond to nothing real.
The three mistakes below show up in account audits again and again. All of them can be found in an afternoon, provided somebody looks.
The conversion is counted more than once
The most common case: the tracking code is deployed through a tag manager and also hard-coded into the thank-you page template. Every order is then counted twice. The campaign looks twice as good as it is, and the algorithm learns on duplicated data.
It is easy to detect — compare the conversion count in the ad platform against the order count in the merchant’s own system for the same period. When the figures differ by tens of percent, attribution is not the explanation.
The conversion measures something without value
The second frequent situation arises when add-to-cart or a contact page view is set as the conversion. These actions happen often, so the campaign looks successful, while its connection to actual revenue is loose at best.
For service businesses it is starker still. An inquiry, a qualified inquiry and a signed contract are three different numbers, and the gap between the first and the last is routinely tenfold. A campaign steered by the wrong one spends on leads the sales team will never close.
Conversion value is never passed
The third mistake is the quietest. Conversions are measured correctly but without value — so the algorithm treats a CZK 200 order as worth exactly as much as a CZK 20,000 one.
Across a range with varying margins this leads to selling most of whatever earns least. The fix is to pass not only order value into tracking but, ideally, margin itself.
What to do about it
Before launching, check three things. Whether the conversion is counted exactly once. Whether it measures an action that genuinely brings the business money. And whether it carries a value you can steer a budget by.
It is an afternoon’s work that determines whether everything following it is of any use. A campaign on broken tracking cannot be rescued by better optimisation — because it optimises toward the wrong target.