A twelve-ounce bottle of sauce is close to the worst possible marketplace product. It is heavy for its price, it breaks, it takes cubic feet in a fulfilment centre, and it competes against a shelf of near-identical bottles from people who also won a competition. Every Kansas City sauce, rub and spice brand that has tried Amazon casually has discovered the same thing: the orders arrive and the money does not. That is not a reason to stay off the channel. It is a reason to build the marketplace assortment differently from the store assortment.
The strategic point first, because it governs everything else. A marketplace is rented shelf space — the buyer belongs to the platform, the fees are theirs to change, and the ranking you earn is not an asset you own. We use it for the thing it does better than your Shopify store ever will, which is putting a bottle in front of somebody who has never eaten in this city. Then the reorder is engineered to come home: larger formats, gift sets, sampler boxes and subscription cadence that only exist on your own store, an insert in the box, and the Brand Registry tools Amazon permits. We do not claim we can move marketplace buyers into your Klaviyo list, because that is not something a seller is allowed to do and pretending otherwise gets accounts suspended.
Operationally, this is a fulfilment and pack-architecture problem more than an advertising one. Multi-packs and bundles change the price-to-weight ratio that makes or breaks the unit economics. Size tiers, dimensional weight and the peak storage rates that apply from October decide what should ever enter FBA at all. Food listings carry their own compliance layer — expiry and date-coding requirements, ingredient and claim language, and the extra category rules that apply to pet and animal-health products where a supplement claim is the difference between a live listing and a suppressed one. All of that gets modelled per SKU before a listing goes up, and read afterwards against contribution margin rather than ACoS on its own.