SD Seller Digest

Glossary

Every guide's key terms link here. Terms link back to the pillar where they're used most.

Marketplace mechanics

ASIN Amazon Standard Identification Number — the unique 10-character identifier Amazon assigns to every product in its catalog. → Listings & Catalog Management
SKU Stock Keeping Unit — your own internal identifier for a specific product/variant, used across every channel you sell on. → Listings & Catalog Management
UPC / EAN / GTIN Universal Product Code, European Article Number, and Global Trade Item Number — standardized barcodes used to uniquely identify products across retailers and marketplaces. → Listings & Catalog Management
Buy Box / Featured Offer The default, one-click-purchase offer shown on a shared product page when multiple sellers list the same item; winning it is based on price, fulfillment method, and seller performance. → Marketplace Operations & Account Health
Brand Registry Amazon's program (requiring a registered trademark) that unlocks enhanced brand content, storefronts, and stronger counterfeit-protection tools. → Legal, Compliance & Risk
Catalog suppression When a marketplace removes a listing from search/browse (but not necessarily deletes it) due to a policy or data-quality issue, until the issue is fixed. → Listings & Catalog Management
IPI score Amazon's Inventory Performance Index — a score reflecting how efficiently you're managing FBA inventory, which affects your storage limits. → Inventory Management
Account health A marketplace's rollup of your performance metrics (defect rate, shipping performance, policy compliance) into a status that determines whether you can keep selling. → Marketplace Operations & Account Health
Referral fee The percentage-of-sale-price fee a marketplace charges for facilitating a sale, varying by category. → Pricing & Profitability
FBA / WFS Fulfillment by Amazon / Walmart Fulfillment Services — programs where the marketplace stores, picks, packs, and ships your inventory on your behalf. → Fulfillment & Logistics
Marketplace facilitator A legal designation under which the marketplace itself (not the individual seller) is responsible for collecting and remitting sales tax on transactions. → Payments, Tax & Financial Operations
Ungating The approval process required to sell in a restricted/gated category on a marketplace, typically requiring supplier invoices or brand approval. → Start Selling on Marketplaces
Star Seller Etsy's seller-recognition program for shops that consistently meet response-time, shipping, and rating benchmarks. → Marketplace Operations & Account Health
Seller Standards eBay's performance program tracking defect rate, case rate, and late shipment rate, which determines your seller level and search visibility. → Marketplace Operations & Account Health
Prime badge The visual indicator on Amazon showing an item is eligible for Prime shipping speeds, available via FBA or Seller Fulfilled Prime. → Fulfillment & Logistics

Advertising

ACOS Advertising Cost of Sale — ad spend divided by ad-attributed revenue, expressed as a percentage. Lower is generally better. → Marketplace & Retail Media Advertising
TACOS Total Advertising Cost of Sale — ad spend divided by total revenue (not just ad-attributed revenue), a better long-term efficiency measure than ACOS alone. → Marketplace & Retail Media Advertising
ROAS Return on Ad Spend — ad-attributed revenue divided by ad spend, the inverse framing of ACOS. → Marketplace & Retail Media Advertising
Retail media Advertising sold directly by a retailer/marketplace on its own site or app, leveraging its first-party shopper data. → Marketplace & Retail Media Advertising
Incrementality The portion of a sale genuinely caused by an ad, as opposed to a sale that would have happened anyway — measured by holdout tests, not just attributed conversions. → Analytics & Measurement
Automatic vs. manual targeting Automatic targeting lets the platform choose which searches trigger your ad; manual targeting lets you specify exact keywords or products. → Marketplace & Retail Media Advertising
Negative keywords Search terms you explicitly exclude from triggering your ad, used to cut wasted spend on irrelevant traffic. → Marketplace & Retail Media Advertising

Finance & operations

Contribution margin Revenue minus all variable costs (COGS, fees, shipping, variable ad spend) for a sale — what's left to cover fixed costs and profit. → Pricing & Profitability
Gross margin Revenue minus cost of goods sold (COGS) only, expressed as a percentage of revenue. → Pricing & Profitability
Landed cost The true, fully-loaded cost of a unit once it's in your warehouse — product cost plus freight, duties, and import fees. → Product Sourcing & Supply Chain
MOQ Minimum Order Quantity — the smallest quantity a supplier will accept per order. → Product Sourcing & Supply Chain
Incoterms Standardized international trade terms (e.g., FOB, EXW, DDP) defining who is responsible for shipping, insurance, and customs at each stage. → Product Sourcing & Supply Chain
Chargeback A forced reversal of a payment initiated by the buyer's card issuer or payment provider, typically due to a dispute. → Marketplace Operations & Account Health
1099-K A U.S. tax form marketplaces and payment processors issue reporting the gross payment volume processed on your behalf. → Payments, Tax & Financial Operations
Safety stock Extra inventory held above expected demand to buffer against demand variability or supply delays. → Inventory Management
Reorder point The inventory level at which you should place a new purchase order to avoid stocking out before the new stock arrives. → Inventory Management
SKU rationalization The process of reviewing a catalog and cutting SKUs that no longer justify the operational cost of carrying them. → Product Research & Assortment Strategy
Break-even ROAS The minimum Return on Ad Spend at which an advertised sale is still profitable, given the product's margin. → Pricing & Profitability
CAC Customer Acquisition Cost — total marketing/sales spend divided by the number of new customers acquired in a period. → Ecommerce Marketing
LTV Customer Lifetime Value — the total revenue or margin a customer is expected to generate over their relationship with your business. → Ecommerce Marketing
Sales tax nexus The connection between a business and a state/jurisdiction sufficient to require that business to collect and remit sales tax there. → Payments, Tax & Financial Operations
MAP Minimum Advertised Price — a policy set by a brand/manufacturer specifying the lowest price at which resellers may advertise a product. → Pricing & Profitability

Sourcing & compliance

Private label Products manufactured by a third party but sold under your own brand name. → Product Sourcing & Supply Chain
White label A generic product manufactured once and sold under multiple different sellers' own brand names. → Product Sourcing & Supply Chain
QC (Quality Control) inspection A pre-shipment inspection process (often via a third-party inspection service) verifying that a production run meets your quality specifications. → Product Sourcing & Supply Chain
Prop 65 A California law requiring warning labels on products that contain certain chemicals, enforced regardless of where the seller is based if selling into California. → Legal, Compliance & Risk
GPSR The EU's General Product Safety Regulation, imposing safety and traceability requirements on products sold into the EU market. → Legal, Compliance & Risk
VAT Value Added Tax — a consumption tax applied in the EU, UK, and many other countries at each stage of the supply chain. → International & Cross-Border Ecommerce
DDP / DDU Delivered Duty Paid / Delivered Duty Unpaid — Incoterms specifying whether the seller (DDP) or buyer (DDU) is responsible for import duties. → International & Cross-Border Ecommerce

Technology

PIM Product Information Management system — centralizes and syncs product data (titles, attributes, images) across every channel. → Technology & Integrations
OMS Order Management System — centralizes order processing and routing across every sales channel and fulfillment location. → Technology & Integrations
ERP Enterprise Resource Planning system — integrates core business processes (finance, inventory, purchasing) into one system of record. → Technology & Integrations
WMS Warehouse Management System — manages inventory location, picking, and packing within a physical warehouse. → Technology & Integrations
SP-API Amazon's Selling Partner API — the current API surface for catalog, orders, inventory, and reporting, replacing the older MWS API. → Technology & Integrations
Feed A structured file (or API payload) used to bulk-create or bulk-update listings, inventory, or pricing on a marketplace. → Listings & Catalog Management
Middleware Software that connects and synchronizes data between two or more systems (e.g., your ecommerce platform and a marketplace) that don't natively talk to each other. → Technology & Integrations