How do you decide whether Buy with Prime is profitable?
Run a controlled test on eligible products and compare incremental completed orders and contribution with the same site's prior or holdout experience. Buy with Prime can place Prime checkout and delivery benefits on a seller's own ecommerce site, but a conversion increase should not be treated as guaranteed or automatically profitable.
Amazon states that cost per order depends on factors including dimensions, weight, average order value, and units per order, and can include fulfillment, storage, payment processing, and other services. Use the current product-level pricing and actual transaction data for the decision.
Select products that can support a clean test
- Stable traffic, price, product detail, and inventory during the comparison period.
- Eligible inventory available in Amazon fulfillment centers with enough cover for both channels.
- Known dimensions, weight, landed cost, return rate, and contribution before the program.
- A product where Prime delivery and checkout can plausibly remove a measured purchase barrier.
- No simultaneous redesign, promotion, traffic-source change, or tracking migration that obscures the result.
Build the complete order economics
Start with net merchandise revenue and subtract discounts, program and payment costs, fulfillment, storage allocation, landed product cost, returns allowance, customer service, and the marketing cost that generated the session. Calculate contribution per order and contribution per visitor.
Compare single-unit and multi-unit baskets separately. A higher order value can improve some economics while additional units, weight, packaging, or split inventory create different fulfillment and stock consequences.
Measure incrementality and customer experience
- Eligible product-page sessions, checkout starts, completed orders, units per order, and net revenue.
- Contribution per visitor, customer-acquisition cost, and total incremental contribution.
- Promised versus actual delivery, cancellations, returns, refunds, and customer contacts.
- Inventory availability on the ecommerce site and Amazon marketplace during the same period.
- New and returning customer behavior without assuming every program order is a new customer.
Set expansion and stop rules before launch
Define the minimum sample, contribution floor, inventory-cover floor, service threshold, and review date before the test begins. Expand by product group only when the result remains positive after returns and when fulfillment-center stock can support both site and marketplace demand.
Eligibility, integrations, supported features, program charges, and inventory requirements can change. Confirm the current Buy with Prime and Amazon Supply Chain Services account requirements, pricing, and product status before launch or expansion.