amazon fmb is a likely misspelling of “FBM,” which stands for Fulfilled by Merchant. FBM is a fulfillment method where the seller manages the storage, packing, and shipping of their products. This contrasts with Fulfillment by Amazon (FBA), where Amazon handles these tasks for the seller. FBM is ideal for sellers who prefer more control over their operations or those who have smaller volumes of inventory. By choosing FBM, sellers can save on FBA fees but must manage fulfillment logistics on their own.