False Positives, Real Costs
Stop crediting the wrong channel.
Paid media has an accounting problem. A single sale is often claimed by several advertising channels. Each platform’s report shows a win. The company has one customer and one order. The difference between platform credit and real revenue creates persistent waste.
The root cause is how attribution works. Every large platform measures its own impact inside its own system. It sets rules for how long after an ad a purchase can be counted. It then credits itself when a purchase falls inside that window. Other platforms run the same process. None of them are required to reconcile results with each other or with the company’s source-of-truth sales data. The outcome is systematic double counting.
Incentives keep this in place. Platforms are paid when ads are delivered and when conversions are credited. Agencies are judged on the same platform numbers. Internal teams request budget using those reports. Proving whether an ad created a sale that would not have happened anyway takes more effort. It requires tests and clean data. As a result, credited conversions win budget decisions while true incremental impact is underweighted.
Attribution windows make the gap worse. One platform may count a purchase that happens within 28 days of seeing an ad. Another may count a purchase within seven days of a click. Both can claim the same order. Branded search soaks up demand created by other channels or by offline factors, then appears highly efficient. Retargeting focuses spend on people already likely to buy. Reported return looks strong. Unit economics do not improve.
Identity gaps also play a role. Cookies expire. Mobile IDs reset. Walled gardens block user-level matching. Privacy changes reduce the ability to connect ad exposure to a final sale. To fill the holes, platforms increase modeled conversions. Confidence drops while the slides stay positive. Finance receives a consistent story without a clear counterfactual.
False positives create real costs. Budgets move toward channels that “harvest” demand rather than create it. Frequency rises on the same reachable customers. Paid media crowds out organic sales. The invoice grows while contribution margin stalls. Opportunity cost increases as under-credited channels are cut.
Winners and losers are predictable. Platforms benefit when their reports show more credited sales. Intermediaries and teams with KPIs tied to those reports also benefit. The advertiser pays the bill. The CFO carries the cost of conversions that are not new revenue.
The fix is practical and financial. Change the unit of proof from credited conversions to incremental ones. Run simple experiments that create a counterfactual: holdouts, geo splits, time-based pauses, audience exclusions. Where tests are limited, deduplicate conversions at the enterprise level using server-side logs and privacy-safe clean rooms. Standardize attribution windows across platforms. Separate branded search and retargeting into their own incrementality tests. Apply frequency caps based on diminishing returns, not habit.
Governance should look like control testing. Report two columns: credited results and incremental results. Reconcile the difference and put a dollar figure on over-crediting. Track the share of spend that is incremental, neutral, or negative. Tie commercial terms and agency incentives to the proportion of spend that meets an incrementality threshold. Move budget only when the evidence clears that bar.
Media Audit Group turns these steps into routine practice. We do not buy media or sell ad tech. We review contracts, tags, platform exports, and server logs. We quantify the cost of double counting and paid cannibalization. We translate findings into enforceable terms, exclusion lists, and pacing rules that finance can monitor. The aim is straightforward: pay for new revenue and stop funding credit inflation.
For CFOs and Finance Leaders
A paid media audit focused on incrementality, deduplication, and uniform windows improves media efficiency and reduces waste. Build marketing governance that reconciles platform claims to financial reality and demands advertising accountability tied to lift, not credit.
About Media Audit Group
Media Audit Group provides independent audits of paid media investments for corporate finance and procurement teams. Modeled on traditional financial assurance practices, the firm applies forensic accounting principles to digital advertising—tracing spend, verifying performance, and identifying structural inefficiencies across agency and platform ecosystems. Headquartered in Ontario, Canada, Media Audit Group operates internationally through a network of affiliated partners.