How to actually read Amazon's fee schedule

Amazon's fees come in layers: referral fees (a percentage of each sale, by category), fulfillment fees if you use FBA, storage fees, and a growing set of surcharges.

The ones that hurt are the quiet percentage changes — a referral fee moving from 8% to 9% on a category doesn't sound like much until you multiply it across your volume.

Watch for: category-specific referral-fee updates, changes to FBA size tiers, and new or increased surcharges. When any of these move, re-run your margins before the effective date — not after.