FBM
Also known as: Fulfillment by Merchant, Merchant Fulfilled
Sellers ship inventory directly to customers from their own warehouse (or 3PL) instead of using FBA.
FBM (Fulfillment by Merchant, sometimes called "Merchant Fulfilled Network" or MFN) means the seller is responsible for storing, packing, and shipping orders directly to customers. Amazon handles the marketplace; you handle the logistics.
FBM sellers don't pay FBA fees, which makes the model attractive for oversized items, low-velocity SKUs, hazmat products, brand-restricted listings, and any product where FBA storage + fulfillment fees would exceed margin. The trade-offs are real: FBM listings get a smaller Buy Box weighting (Amazon's algorithm favors FBA), customers don't see Prime badges by default unless you qualify for Seller Fulfilled Prime, and you're responsible for hitting Amazon's shipping and customer service performance metrics.
Many sellers run hybrid: FBA for fast-moving core catalog, FBM for slow-mover fade-outs and oversized items. SellerVault's repricer treats FBA and FBM as separate competitive pools so you can have different rules per fulfillment channel on the same ASIN.