Platform fees, margin math, and FBA cost breakdowns for sellers who want to understand their real profits.
Most FBA sellers track referral fees and FBA fees. The sellers who stay profitable long-term also track storage, returns, PPC, aged inventory, and inbound shipping. Here's the full cost breakdown.
Discounting feels like a growth tool. The contribution margin math shows it's often a trap. Here's exactly how many additional units you need to sell to break even on any discount.
A $40 product feels profitable. After platform fees, payment processing, shipping, and returns, that margin can drop below 10%. Here's the actual math platform by platform.