Amazon FBM vs FBA: which profit number matters?
How to compare seller-fulfilled and FBA economics without hiding labour, postage or fulfilment risk.
FBM is not free fulfilment
Seller fulfilment avoids FBA fees, but it does not avoid work. Postage, packaging, picking time and customer service still belong in the model.
If you ignore your own fulfilment cost, FBM can look artificially strong.
FBA buys convenience and conversion
FBA can help conversion and delivery expectations, but the benefit has to be large enough to pay for the fulfilment cost.
Use FBA scenarios for products where faster delivery, Prime eligibility or operational simplicity could realistically improve sales.
Compare the same customer promise
Do not compare slow FBM postage with fast FBA as if the customer experience is identical. Delivery speed can change both conversion and review risk.
The clean comparison is profit plus operational fit, not fee line alone.