Amazon has updated its fee schedule three times in the last eighteen months, and each round quietly resets the profit math for thousands of sellers who never re-ran their numbers. If the last time you checked your true landed cost was when you launched the product, there is a good chance your real margin looks different today.
Start with the basics: pull your referral fee category, your current FBA fulfillment fee tier, and your average monthly storage cost per unit. Multiply all three against your actual sell-through rate, not your best month. Sellers are consistently surprised by how much aged inventory surcharges and long-term storage fees eat into categories that look healthy on paper.
The fix is not always a price increase. Sometimes it is a packaging change that drops you into a lower size tier, a shift from case-pack to individual units, or renegotiating your COGS with a supplier now that volume has grown. Run the comparison across both Fulfilled by Amazon and self-fulfillment before assuming FBA is still the cheaper option for every SKU in your catalog.
Whatever you decide, put a recurring quarterly review on the calendar. Fee structures change on Amazon’s schedule, not yours, and the sellers who stay profitable are the ones who check the math before the fee hits, not after the profit report tells them something went wrong.