Stack Portability Discount

Stack Portability Discount is the valuation haircut an agency should apply to lifecycle expertise that only works inside one vendor's environment. The category's leverage comes from recurring retainer work around retention and upsell, but that leverage is fragile when the workflow logic lives in a single platform's journey builder rather than in the agency's own method. A team fluent in Customer.io's behavioral segmentation or Iterable's AI decisioning can still lose a client the moment that client migrates to a Shopify-native stack and the agency has to rebuild from zero. The discount is the cost of that rebuild, measured in onboarding hours and lost continuity. Agencies that document trigger logic, segment definitions, and measurement baselines in vendor-neutral form can re-deploy the same thinking on Stamped or BonusQR in days instead of weeks, which keeps the retainer defensible when procurement pressure arrives.