The campaigns run. Spend goes out. Conversions come back. But somewhere between Quality Score, audience signals, and conversion-side measurement, 20-40% of the budget is being burned on traffic that was never going to convert. The agency sends a weekly report. The numbers look fine on the surface. Growth stalls.
Three failure modes show up almost every time. One: Performance Max running blind without first-party signals, customer match lists, or excluded categories — Google's algorithm optimising against a brand's own retargeting pool. Two: Conversion tracking deduplicating poorly across GA4, Google Ads, and the merchant's own database — so every channel claims the same sale. Three: Account architecture built for reporting convenience, not bidding logic — campaigns grouped by product line when they should be grouped by margin or lifetime value.
These aren't problems junior account managers can see. They require senior eyes on the account, and senior eyes don't come cheap when an agency is paying account managers $65k and billing $4k retainers. The maths only works at scale, which means you get scale-economy attention regardless of how much you spend.
That's the model we built Arche to replace.