An agency sells a promise — reach, impressions, viewability, a delivered schedule — and then has to make that promise true across thousands of line items, dozens of markets and a calendar that never stops. The economics are unforgiving in a specific way: when delivery falls short of what was guaranteed, the agency owes a makegood, free inventory handed over to settle the gap. A makegood is margin given away after the fact for a problem that was usually visible, in the data, days before anyone acted on it. At volume, those small, late corrections compound into a real and recurring drag on profitability.
The harder version of the problem is the shortfall nobody catches. A campaign under-delivers, no one notices before the invoice goes out, and either the client finds it — which costs trust as well as money — or it simply becomes an unbilled loss absorbed quietly into the numbers. Multiply a small leakage rate across hundreds of clients and the figure stops being a rounding error. This is the gap a quality model is supposed to close, and the reason manual, end-of-cycle checking fails: there is too much to inspect, the checks are not placed where the money actually leaks, and coverage cannot be proven when a client asks what was actually reviewed.
The approach I bring is staged QA built to run at volume, not heroic checking that collapses under it. At a global advertising network, a three-step makegoods QA framework protected more than USD 20 million in client billings — not by inspecting everything, but by placing the heaviest verification exactly where exposure was greatest and catching shortfalls while they were still correctable. The same discipline lifted a quality score from 95% to 99% across more than 2,000 campaigns and 450 clients. The point is consistency that holds across teams and markets, and coverage you can prove rather than assert.