Amazon Seller Glossary: 80+ Terms Every FBA Seller Should Know
A comprehensive reference of every Amazon selling term you need to understand, organized by category with clear definitions and practical context. Bookmark this page and come back whenever you encounter an unfamiliar term.
Whether you are just starting your Amazon selling journey or have been at it for years, the Amazon ecosystem is packed with acronyms, metrics, and concepts that can be confusing. This glossary covers over 80 terms organized into six categories so you can quickly find what you need.
How to Use This Glossary
Use your browser's find feature (Ctrl+F or Cmd+F) to jump directly to any term. Each section is organized alphabetically within its category. Where applicable, terms link to SellerKit calculators and tools so you can put the concept into practice immediately.
Account & Selling Terms
Core terms related to your Amazon seller account, product identifiers, and the fundamental infrastructure of selling on the platform.
| Term | Definition |
|---|---|
| A+ Content | Enhanced product description available to brand-registered sellers that allows rich media such as comparison charts, lifestyle images, and custom text layouts below the bullet points on a listing. Replaces the plain-text product description and can improve conversion rates by 3–10%. |
| Amazon Vine | An invitation-only review program where Amazon sends your product to trusted reviewers (Vine Voices) in exchange for honest reviews. Sellers enroll ASINs and pay a fee per parent ASIN. Useful for generating initial reviews on new product launches. |
| ASIN | Amazon Standard Identification Number. A unique 10-character alphanumeric identifier assigned by Amazon to every product in the catalog. Each variation (size, color) has its own ASIN. You need the ASIN to look up any product on Amazon. |
| Brand Registry | Amazon's program for trademark-registered brands that unlocks tools such as A+ Content, Sponsored Brands ads, Brand Analytics, and enhanced IP protection. Requires an active registered trademark. |
| BSR (Best Seller Rank) | A ranking assigned to every product in each category based on recent and historical sales velocity. Lower BSR means higher sales volume. BSR updates hourly and is relative to other products in the same category. Use the BSR Sales Estimator to convert BSR into estimated daily or monthly unit sales. |
| Buy Box | The featured offer section on a product detail page where customers click “Add to Cart.” When multiple sellers offer the same ASIN, Amazon rotates the Buy Box among eligible sellers based on price, fulfillment method, seller metrics, and availability. Winning the Buy Box is essential for generating sales. |
| EAN | European Article Number. A 13-digit barcode standard used internationally. Equivalent to the UPC in Europe and recognized by Amazon for product identification. |
| Early Reviewer Program | A now-discontinued Amazon program that encouraged buyers who already purchased a product to leave a review in exchange for a small gift card. Replaced largely by the Vine program. |
| Enhanced Brand Content (EBC) | The former name for A+ Content. Some sellers and resources still use this term. Functionally identical to A+ Content. |
| FBA | Fulfillment by Amazon. A service where sellers send inventory to Amazon's warehouses and Amazon handles storage, picking, packing, shipping, customer service, and returns. FBA products are eligible for Prime shipping, which significantly boosts conversion rates. Compare costs with the FBA vs FBM Calculator. |
| FBM | Fulfillment by Merchant. The seller handles all storage, shipping, and customer service themselves (or through a third-party logistics provider). FBM avoids FBA fees but typically has lower conversion rates because products are not Prime-eligible unless the seller qualifies for Seller Fulfilled Prime. |
| FNSKU | Fulfillment Network Stock Keeping Unit. Amazon's internal barcode that ties a specific product to a specific seller in FBA. Each FNSKU label must be applied to every unit before sending inventory to Amazon. |
| GTIN | Global Trade Item Number. The umbrella standard that includes UPC, EAN, ISBN, and other barcode formats. Amazon accepts GTINs for product identification during listing creation. |
| Seller Central | The web portal where third-party sellers manage their Amazon business, including listings, inventory, advertising, orders, reports, and account settings. This is your main dashboard for everything on Amazon. |
| SKU | Stock Keeping Unit. A seller-defined alphanumeric identifier used to track inventory internally. Each product variation you sell gets a unique SKU. Unlike ASINs, you create your own SKUs and can structure them to encode information like supplier, color, and batch. |
| UPC | Universal Product Code. A 12-digit barcode standard used primarily in North America. Required by Amazon for most new product listings unless you have a GTIN exemption through Brand Registry. |
ASIN vs SKU vs FNSKU
These three identifiers confuse many new sellers. The ASIN is Amazon's catalog-level ID shared across all sellers of the same product. The SKU is your internal tracking code. The FNSKU is Amazon's warehouse-level barcode that links a physical unit to your seller account. When you send inventory to FBA, each unit needs an FNSKU label.
Fees & Financial Terms
Understanding fees and financial metrics is critical for maintaining profitability. For a deep dive into every Amazon fee, see the Amazon FBA Fees Explained guide.
| Term | Definition |
|---|---|
| Aged Inventory Surcharge | An additional monthly fee charged on FBA inventory that has been stored in Amazon's warehouses for more than 180 days. The surcharge increases at 30-day intervals and becomes significant after 365 days. Formerly called Long-Term Storage Fees. |
| Break-even Point | The sale price or unit volume at which total revenue exactly covers total costs (COGS + all Amazon fees + advertising + overhead), resulting in zero profit. Knowing your break-even point helps you set minimum viable prices and advertising budgets. |
| Closing Fee | A fixed per-unit fee ($1.80) charged on media items such as books, DVDs, music, and video games, in addition to the referral fee. |
| COGS | Cost of Goods Sold. The total cost to acquire or manufacture one unit of your product, including material costs, manufacturing, packaging, and freight to Amazon. COGS is the foundation of every profit calculation. Use the FBA Profit Calculator to see how COGS impacts your margins. |
| FBA Fulfillment Fee | A per-unit fee Amazon charges for picking, packing, and shipping FBA orders. The amount depends on the product's size tier and shipping weight. This is typically the second-largest Amazon fee after the referral fee. |
| Gross Margin | The percentage of revenue remaining after subtracting COGS: (Revenue − COGS) / Revenue × 100. Gross margin does not account for Amazon fees, advertising, or overhead. Use the Profit Margin Calculator to compute this instantly. |
| Inbound Placement Fee | A per-unit fee charged when you choose to ship inventory to fewer Amazon fulfillment centers instead of using Amazon's default optimized split shipments. Avoidable by accepting shipments to multiple locations. |
| Monthly Storage Fee | A per-cubic-foot fee assessed monthly for storing inventory in Amazon's fulfillment centers. Rates vary by size tier and are significantly higher during Q4 (October–December). Estimate your costs with the Storage Fee Calculator. |
| Net Margin | The percentage of revenue remaining after all costs are deducted, including COGS, Amazon fees, advertising spend, and overhead: (Revenue − All Costs) / Revenue × 100. A healthy Amazon private-label product typically targets 20–30% net margin. |
| Referral Fee | A percentage-based commission Amazon charges on every sale, calculated on the total sale price including shipping charged to the customer. The rate varies by category (typically 8–17%, most commonly 15%). Look up exact rates with the Referral Fee Lookup tool. |
| Refund Administration Fee | When you issue a customer refund, Amazon refunds your referral fee but keeps a portion as an administration fee: $5.00 or 20% of the original referral fee, whichever is less. |
| Return Processing Fee | A fee charged per returned unit in categories where Amazon provides free customer returns (apparel, shoes, watches, jewelry). The fee equals the original FBA fulfillment fee for that item. |
Fees Can Consume 30–40% of Your Sale Price
For a typical standard-size product, referral fees, FBA fulfillment fees, and storage fees combine to take roughly 30% of the sale price. Add advertising costs and the total can reach 40% or more. Always model your full fee stack before sourcing a product. See How Amazon Fees Affect Profit for worked examples.
PPC & Advertising Terms
Amazon PPC (Pay-Per-Click) advertising is how most sellers drive traffic and launch products. These terms are essential for managing your ad campaigns effectively.
| Term | Definition |
|---|---|
| ACOS | Advertising Cost of Sale. The ratio of ad spend to ad revenue, expressed as a percentage: (Ad Spend / Ad Revenue) × 100. An ACOS of 25% means you spent $0.25 in ads for every $1.00 in ad-attributed sales. Lower is generally better, but the target depends on your profit margins. Calculate your target with the Break-Even ACOS Calculator. |
| Automatic Campaign | A Sponsored Products campaign where Amazon chooses which search terms and product pages to show your ads on, based on your listing content. Useful for keyword discovery but offers less control than manual campaigns. |
| Bid | The maximum amount you are willing to pay for a single click on your ad. Amazon uses a second-price auction model, so you typically pay slightly more than the next highest bidder rather than your full bid amount. |
| CPC | Cost Per Click. The actual amount you pay each time a shopper clicks on your ad. CPC varies by keyword competitiveness, relevance, and your bid strategy. Average CPCs on Amazon range from $0.50 to $3.00+ depending on the niche. |
| CTR | Click-Through Rate. The percentage of shoppers who click your ad after seeing it: (Clicks / Impressions) × 100. A healthy CTR for Sponsored Products is typically 0.3–0.5%+. Low CTR usually indicates your main image, title, price, or review count needs improvement. |
| CVR (Conversion Rate) | The percentage of ad clicks that result in a purchase: (Orders / Clicks) × 100. A strong Amazon conversion rate is typically 10–15%+. Low CVR from ads suggests your listing content, pricing, or reviews need work. |
| Daily Budget | The maximum amount you are willing to spend per day on a single ad campaign. Amazon may exceed the daily budget on high-traffic days but will stay within your monthly average. Use the PPC Budget Calculator to plan your spend. |
| Impressions | The number of times your ad is displayed to shoppers. An impression does not mean the shopper noticed or interacted with your ad, only that it was rendered on their screen. |
| Manual Campaign | A Sponsored Products campaign where you choose exactly which keywords or product ASINs to target with your ads. Offers precise control over targeting and bids, making it the preferred campaign type for optimizing performance. |
| Negative Keywords | Keywords you explicitly exclude from triggering your ads. Adding negative keywords prevents your ads from showing on irrelevant searches, reducing wasted ad spend. Essential for lowering ACOS. |
| ROAS | Return on Ad Spend. The inverse of ACOS: (Ad Revenue / Ad Spend). A ROAS of 4.0 means you earned $4.00 in revenue for every $1.00 spent on ads. ROAS and ACOS are two ways to express the same metric; Amazon reports use ACOS more frequently. |
| Search Term Report | A downloadable report from Seller Central that shows every actual search query that triggered your ads, along with impressions, clicks, spend, and sales data per search term. The primary tool for finding winning keywords and negative keyword candidates. |
| Sponsored Brands | An ad format available to brand-registered sellers that displays your brand logo, a custom headline, and multiple products at the top of search results. Effective for brand awareness and driving traffic to your Brand Store. |
| Sponsored Display | An ad format that targets shoppers on and off Amazon based on shopping behavior, product views, or specific audiences. Ads can appear on product detail pages, customer review pages, and external websites. |
| Sponsored Products | The most common Amazon ad format. Ads appear in search results and on product detail pages, looking similar to organic listings. Available to all sellers. This is where most sellers start and where the majority of ad spend goes. |
| TACoS | Total Advertising Cost of Sale. Total ad spend divided by total revenue (organic + ad-attributed): (Total Ad Spend / Total Revenue) × 100. TACoS gives a more holistic view of how advertising impacts overall profitability. A decreasing TACoS over time means organic sales are growing relative to ad spend. Track it with the TACoS Calculator. |
The Relationship Between ACOS and Profit Margin
Your break-even ACOS equals your pre-advertising profit margin. If your product has a 30% profit margin before ad spend, any ACOS below 30% means the ad campaign is profitable. Use the Break-Even ACOS Calculator to find your exact threshold. For more context, read What Is Break-Even ACOS?
Product Research Terms
Terms you will encounter when evaluating product opportunities and deciding what to sell on Amazon.
| Term | Definition |
|---|---|
| BSR (Best Seller Rank) | Also listed in Account Terms. In product research context, BSR is the primary indicator of how well a product is selling relative to others in its category. Lower BSR = higher sales. Researchers use BSR to estimate monthly sales volume and validate market demand. Use the BSR Sales Estimator to convert rank into unit estimates. |
| Demand Validation | The process of confirming that sufficient customer demand exists for a product before committing to inventory. Typically involves analyzing BSR of competing products, monthly search volume for primary keywords, review velocity of competitors, and revenue estimates. |
| Lead Time | The total time from placing a purchase order with your supplier to having inventory checked into Amazon's fulfillment centers. Includes manufacturing time, quality inspection, shipping (ocean or air freight), customs clearance, and FBA inbound processing. Typical lead times from China are 30–60 days by sea. |
| MOQ | Minimum Order Quantity. The smallest number of units a manufacturer will produce per order. MOQs vary widely by product and supplier, from 100 to 5,000+ units. Negotiating lower MOQs is important for first orders to reduce risk. |
| Niche | A specific segment of a market focused on a particular product type or customer need. In Amazon selling, a good niche has sufficient demand, manageable competition, and room for product differentiation. |
| Online Arbitrage (OA) | A selling model where you find discounted products on other online retailers and resell them on Amazon at a markup. Similar to retail arbitrage but sourcing is done online. Margins tend to be thinner but it scales more easily. |
| Private Label | A selling model where you source generic products from a manufacturer, add your own brand and packaging, and sell under your brand name. The most popular model for building a long-term Amazon business because you own the listing and control the brand. |
| Product Differentiation | The strategy of modifying or improving a product to stand out from existing competitors. Common approaches include bundling, better materials, improved design, additional accessories, or enhanced packaging. Differentiation helps justify premium pricing and reduces direct competition. |
| Retail Arbitrage (RA) | A selling model where you buy discounted products from physical retail stores (clearance aisles, liquidation sales) and resell them on Amazon for a profit. Low barrier to entry but hard to scale. |
| Wholesale | A selling model where you purchase existing branded products in bulk directly from the brand or an authorized distributor at wholesale prices, then resell on Amazon. You sell established brands rather than your own, so competition for the Buy Box is the main challenge. |
Which Selling Model Is Right for You?
Private label offers the highest margins and long-term brand value but requires the most upfront investment and lead time. Wholesale offers faster turns with established demand but thinner margins. Arbitrage (retail and online) has the lowest barrier to entry but is hardest to scale. Most serious Amazon businesses eventually move to private label or wholesale. Use the Product Research Analyzer to evaluate opportunities.
Inventory & Logistics Terms
Inventory management directly impacts your profitability and sales continuity. Running out of stock kills your organic ranking; overstocking racks up storage fees.
| Term | Definition |
|---|---|
| Case Pack | A group of identical units packed together in a single shipping box for FBA inbound shipments. Amazon may require case-pack quantities for certain shipments. The number of units per case pack is typically defined by the manufacturer. |
| Disposal Order | A request for Amazon to destroy inventory in their fulfillment centers that you no longer want. Disposal is cheaper than removal (having it shipped back to you) and is suitable for damaged, expired, or obsolete stock. |
| Inbound Shipment | A shipment of inventory you send to Amazon's fulfillment centers. Created through Seller Central's “Send to Amazon” workflow, where you specify products, quantities, and prep requirements. Amazon assigns destination warehouse(s). |
| IPI Score | Inventory Performance Index. A metric (0–1000) that measures how efficiently you manage FBA inventory. Factors include excess inventory percentage, sell-through rate, stranded inventory percentage, and in-stock rate. A low IPI score (below 400) can trigger storage volume limits. |
| Lead Time | In inventory context, the number of days between placing a reorder with your supplier and having that inventory available for sale in Amazon's warehouses. Accurate lead time estimates are critical for calculating when to reorder. Use the Inventory Reorder Calculator to compute your ideal reorder point. |
| Overstock | Having significantly more inventory than you can sell in a reasonable timeframe. Overstock ties up capital and incurs monthly storage fees plus aged inventory surcharges if units sit too long. |
| Removal Order | A request for Amazon to ship your FBA inventory back to you (or to a specified address). You pay a per-unit removal fee. Used for recalling defective products, retrieving inventory for sale on other channels, or avoiding long-term storage fees. |
| Reorder Point | The inventory level at which you should place a new purchase order with your supplier to avoid a stockout. Calculated using your daily sales velocity, lead time, and safety stock level. See the When to Reorder Inventory guide for a detailed walkthrough. |
| Safety Stock | Extra inventory held as a buffer against unexpected demand spikes or supplier delays. Typically calculated as a multiple of average daily sales multiplied by the variability in lead time. Running without safety stock increases your risk of stockouts. |
| Stockout | When your inventory reaches zero units available on Amazon. A stockout stops all sales, pauses active PPC campaigns, and can cause your organic keyword rankings to drop significantly. It often takes weeks to recover lost ranking after restocking. Read How to Avoid Stockouts for prevention strategies. |
| Stranded Inventory | Inventory stored in Amazon's warehouses that is not associated with an active listing, meaning it cannot be sold. Common causes include listing errors, suppressed listings, or ASIN deactivations. Stranded inventory still incurs storage fees. Check the Fix Stranded Inventory page in Seller Central regularly. |
| Velocity | The rate at which a product sells, typically measured in units per day or units per month. Sales velocity directly affects inventory planning, reorder timing, and BSR. Use the Sales Estimator to project velocity for products you are researching. |
Stockouts Are the Most Expensive Inventory Mistake
A single stockout of 7–14 days can drop your organic keyword rankings significantly, taking weeks or even months to recover. The lost sales during the stockout combined with the increased advertising spend needed to regain ranking make stockouts far more costly than carrying a little extra safety stock. Always err on the side of having a buffer.
Listing & SEO Terms
Your product listing is your storefront on Amazon. Optimizing it for both Amazon's search algorithm and customer conversion is essential for success.
| Term | Definition |
|---|---|
| A/B Test (Manage Your Experiments) | Amazon's built-in tool for brand-registered sellers that lets you test two versions of a listing element (title, main image, A+ Content) against each other to see which performs better. Amazon splits traffic and reports statistical significance. |
| Backend Search Terms | Hidden keywords you enter in the “Search Terms” field in Seller Central that help Amazon index your product for relevant searches without showing them to customers. You have 250 bytes of space. Include synonyms, alternate spellings, and related terms not in your visible listing. Use the Listing Character Counter to check your byte usage. |
| Bullet Points | The five key feature bullet points displayed prominently on a product listing. These are a primary factor for both search indexing and customer conversion. Each bullet should lead with a benefit and include relevant keywords naturally. |
| Conversion Rate | The percentage of listing visitors (sessions) who make a purchase: (Orders / Sessions) × 100. Also called Unit Session Percentage in Seller Central. A strong Amazon conversion rate is 10–20%+. Low conversion rate negatively impacts organic ranking. |
| Deindexed | When Amazon's search algorithm no longer returns your listing for a specific keyword, meaning you are invisible for that search term. Can happen if you remove a keyword from your listing, violate keyword guidelines, or if Amazon suppresses your listing. |
| Indexed | When Amazon's search algorithm recognizes your listing as relevant for a given keyword, making it eligible to appear in search results for that term. You can check indexing by searching “ASIN + keyword” on Amazon. A product must be indexed for a keyword before it can rank for it. |
| Main Image | The primary product photo that appears in search results and at the top of your listing. Amazon requires a pure white background with the product occupying at least 85% of the frame. The main image is the single biggest factor in click-through rate from search results. |
| Page Views | The total number of times your product listing page has been viewed, including multiple views by the same shopper. Differs from Sessions, which counts unique visitors. Available in Seller Central Business Reports. |
| Sessions | The number of unique visitors to your product listing within a 24-hour period. One session can include multiple page views. Sessions is the denominator for calculating your conversion rate. |
| Suppressed Listing | A listing that Amazon has hidden from search results because it violates listing guidelines or is missing required information (such as a main image, category, or required product attributes). Suppressed listings generate zero sales until fixed. Check the Listing Quality Dashboard in Seller Central. Use the Listing Quality Checker to catch issues before Amazon does. |
| Title | The product title displayed at the top of your listing and in search results. The most heavily weighted field for Amazon SEO. Should include your primary keyword, brand name, key features, and relevant attributes (size, color, quantity) within Amazon's character limit (typically 200 characters, but varies by category). |
Listing Optimization Priority Order
When optimizing your listing, focus in this order for maximum impact: (1) Main image, because it drives click-through rate from search; (2) Title, because it is the strongest ranking factor; (3) Price, because it directly affects conversion rate; (4) Bullet points, for keyword indexing and persuasion; (5) A+ Content and secondary images, for conversion rate lift; (6) Backend search terms, for additional keyword coverage.
Quick Reference Card
The most commonly used formulas across all Amazon selling terms, collected in one place for fast lookup:
| Metric | Formula |
|---|---|
| ACOS | (Ad Spend ÷ Ad Revenue) × 100 |
| ROAS | Ad Revenue ÷ Ad Spend |
| TACoS | (Total Ad Spend ÷ Total Revenue) × 100 |
| CTR | (Clicks ÷ Impressions) × 100 |
| CVR | (Orders ÷ Clicks) × 100 |
| Gross Margin | (Revenue − COGS) ÷ Revenue × 100 |
| Net Margin | (Revenue − All Costs) ÷ Revenue × 100 |
| Break-even ACOS | Pre-ad Profit Margin % |
| Reorder Point | (Daily Sales Velocity × Lead Time) + Safety Stock |
| Conversion Rate | (Orders ÷ Sessions) × 100 |
Keep Learning
This glossary is a living reference. As Amazon evolves its platform, new terms emerge and existing definitions shift. Pair this glossary with the Amazon FBA Beginner Checklist if you are just getting started, or dive into specific topics through the related guides linked throughout this page.