FNSKU stands for Fulfillment Network Stock Keeping Unit. It's a unique identifier assigned by Amazon to products that sellers specify for fulfillment by Amazon's warehouse system. Essentially, when a sneaker reseller decides to use Amazon's FBA (Fulfillment by Amazon) service, Amazon gives each pair or set of sneakers a specific FNSKU. This identifier is different from the general product's UPC or EAN, as it's tied to both the specific product and the seller. In the world of sneaker reselling on Amazon, the FNSKU ensures that the exact sneakers a seller ships to Amazon's warehouse are the ones a customer receives when they place an order. Think of it as a system to prevent mix-ups. If two sellers are selling the same sneaker model and size but one seller's sneakers are in pristine condition and another's have a slight defect, the FNSKU ensures that each buyer gets the correct pair from the right seller. To utilize FNSKU, sneaker resellers typically print out Amazon's provided labels with the FNSKU code and place them on their products before shipping them to Amazon's warehouse. Understanding and correctly using FNSKU is crucial for sneaker resellers who want to maintain their reputation and ensure a seamless process when selling through Amazon's platform.