Fixing cost-API ingestion: ROAS dashboards were wrong by 13% for a month

Fixing cost-API ingestion: ROAS dashboards were wrong by 13% for a month
A team trusted blended ROAS until they reconciled MMP cost data against network billing. Singular's cost aggregation was pulling pre-discount rate-card spend for two networks, not actual invoiced cost.

The gap: dashboards overstated spend 13%, so ROAS read worse than reality and they'd throttled a profitable channel.

Reconnecting the cost APIs with the correct billing endpoints fixed it; they un-throttled and scaled.

✓ Always reconcile MMP cost against the actual invoice monthly
✓ The error was hiding a profitable channel, not a loss
✗ Cost-API quirks vary per network; no universal fix
✗ Took a manual finance cross-check to even notice

Verdict: trust your ROAS only after cost data matches the invoice.
Best for: teams scaling on blended ROAS dashboards.