Ad platforms optimise toward the conversions you tell them about. Your team allocates budget based on the ROAS it sees. If either signal is wrong, every downstream decision inherits the error, and the cost compounds.
Optimisation follows the signal you send
Platform algorithms learn from your conversion data. If that data is missing conversions, the algorithm optimises toward the wrong audiences. If it's inflated with duplicates, it doubles down on channels that only look profitable. Either way, spend drifts toward the wrong place.
Budget follows the ROAS you report
When ROAS is overstated on one channel, it attracts more budget than it deserves, while genuinely efficient channels get underfunded. Multiply that across months and the opportunity cost is significant.
The compounding cost of bad data
Bad data doesn't waste budget once. It wastes it continuously:
- Wrong optimisation signals train the algorithm incorrectly
- Overstated ROAS misallocates budget month after month
- Missing conversions starve channels that actually work
- Time is lost chasing 'performance problems' that are really data problems
Clean data is the cheapest optimisation
Before spending more or restructuring campaigns, it's worth confirming the data underneath is accurate. Often the biggest performance gains come not from new creative or bidding changes, but from fixing the measurement that was quietly misleading every decision.
Related reading: our services and the Measurement Health Audit.
Think this might be happening in your account?
A Measurement Health Audit traces every conversion end to end and tells you exactly what's duplicated, missing, misfiring, or misaligned.