A practical workflow
Follow the guide step by step
- 01
Match the exact product and variation
Confirm the listing, selected variation, condition, and number of sellable units. A nearby size or multipack may have a different category or package measurement.
- 02
Check the marketplace category
Referral assumptions can vary by category. For Walmart, verify the contract category assigned to the item in seller records; visible listing clues are not proof of the assigned category.
- 03
Measure the packaged sellable unit
Record the packaged dimensions—length, width, and height—and shipping weight for the product in the package state required by the fulfillment program. Do not substitute unpackaged item measurements when packaging changes the dimensions.
- 04
Select the fulfillment method before estimating
Amazon FBA and Walmart WFS use their own classifications and fee rules. Use the matching official estimator or current seller record, and do not transfer a size tier or weight assumption from one marketplace to another.
- 05
Resolve gaps and rerun the audit
If category, dimensions, weight, or eligibility is missing or uncertain, verify it or enter a confirmed fee manually. Keep the result at Review while a material assumption is unresolved.
Category and measurements affect different fee lines
Category primarily determines which referral-fee assumption applies. Package dimensions and shipping weight help determine fulfillment classification and cost. A product can have a well-matched category but still have an unreliable fulfillment estimate if its packed measurements are wrong.
The app reads supported details visible on a product page and applies editable planning assumptions. It does not know that a marketplace has officially assigned a category or fee unless you verify that information in the marketplace's own seller resources.
Do not turn missing measurements into a zero fee
Compare listing details with a current measurement of the packaged unit, especially for bundles, multipacks, heavy products, and items near a size boundary. If values disagree, check that both refer to the same variation and packaging state before choosing one.
Margin Seller surfaces fee-input confidence and diagnostic reasons when an estimate depends on uncertain or unsupported details. Use manual verification and keep the decision at Review instead of treating a missing fee as zero or relying on an extrapolation.
Check category first
Choose the category first, because a wrong category assumption changes the referral fee and every number that depends on it.
Then measure a physical sample of the packed unit, since listing dimensions are sometimes entered for the product instead of the package.
Trace each assumption to the fee line it affects
A useful check separates category uncertainty from package uncertainty. Category affects the referral-fee assumption; packaged dimensions and shipping weight can affect fulfillment classification. Verify each one for the exact marketplace listing and selected variation rather than copying a value from a similar product.
When page data is missing, compare it with a measured packaged unit and the current marketplace estimator or seller record. Margin Seller surfaces fee-input confidence and diagnostic reasons; a missing measurement or unverified category is a prompt for manual verification, not permission to assume a zero charge.
- For Walmart, confirm the assigned contract category in seller records; page clues are not an official assignment.
- Keep Amazon and Walmart classifications separate even when the same item is listed on both marketplaces.
- Leave the result at Review if a material measurement or category remains unresolved.
Common questions
Frequently asked questions
Does product category affect every marketplace fee?
Category can affect referral-fee assumptions, while fulfillment charges also depend on the selected service and its product classification. Check the current rules for each fee line.
Should I use the listing's dimensions or measure the product?
Check both. Confirm that listing values match the exact variation and packaged sellable unit, and use current marketplace instructions for the measurement basis.
What if shipping weight or category is missing?
Verify it through an appropriate seller record, official estimator, or measurement. Do not treat unknown fee-driving data as zero; leave the result for review until the assumption is resolved.
Why does product size change my fee?
Fulfillment fees are set by size tier and weight, so a small change can move the product to a higher tier.
Ready to check a listing?
Put the assumptions to work.
Bring the visible listing facts and your own costs into a product audit before you commit to inventory.