The QA Margin Curve: Why Feedback Loops Decide Fixed-Bid Profit

Fixed-bid agency work is priced on an assumed number of revision cycles, so every vague client email that becomes a second or third round of changes is unbilled delivery time. Testing and QA tooling converts that ambiguity into annotated, timestamped tickets and automated regression checks, which compresses revision rounds and makes the assumed cycle count defensible. The strategic stake is not bug count, it is whether quality assurance is a cost center you absorb or a retainer line you sell.