The QA Margin Curve: Why Feedback Latency Beats Test Coverage in Agency Economics

Agencies win fixed-bid work on revision speed, not defect counts, so the highest-return QA investment is compressing the client feedback loop rather than maximizing automated coverage. Every extra round of "this looks off" email triage burns unbilled hours that a point-and-click annotation layer converts into a scoped ticket. The trap is over-automation: heavy suites add maintenance drag that quietly erodes the speed advantage that won the account.