Amazon Seller Glossary

This amazon seller glossary covers the terms that actually come up in weekly account reviews, agency calls, and Seller Central case logs — defined the way practitioners use them, not the way a press release would. Each entry is one to three sentences: what the term means, and the operational reason you should care. It’s organized by theme rather than alphabetically, because “IPI” only makes sense next to “capacity limits,” not next to “Inauthentic complaint.” Send this page to new hires, your bookkeeper, or the finance director who keeps asking why RoAS and ACoS are “different numbers for the same thing.” (They’re reciprocals. It’s in here.)

Advertising Metrics

ACoS (Advertising Cost of Sales) — Ad spend divided by ad-attributed revenue, expressed as a percentage. A 25% ACoS means you spent $25 to generate $100 of sales that Amazon credits to ads. Useful at the campaign level; misleading at the business level because it ignores organic sales entirely.

TACoS (Total Advertising Cost of Sales) — Ad spend divided by total revenue, organic included. This is the number that tells you whether ads are building the business or propping it up; a flat TACoS with rising revenue means advertising is compounding into organic rank. The full logic is in our breakdown of ACoS vs TACoS.

RoAS (Return on Ad Spend) — Ad revenue divided by ad spend; the mathematical inverse of ACoS. A 4x RoAS equals a 25% ACoS. Amazon’s DSP console reports RoAS while Sponsored Ads reporting leans on ACoS, which is why your finance team thinks you have two metrics when you have one.

CPC (Cost Per Click) — What you pay when a shopper clicks your ad, set by second-price auction. Category CPCs range from under $0.50 in unglamorous B2B niches to $6+ in supplements; rising CPCs with flat conversion is the classic sign of a category getting crowded.

CTR (Click-Through Rate) — Clicks divided by impressions. For Sponsored Products, anything under ~0.2% usually means the ad is showing on irrelevant terms or the main image is losing the shelf; strong ads on relevant exact-match terms run 0.4%+.

CVR (Conversion Rate) — Orders divided by clicks (in ad reports) or units divided by sessions (in Business Reports, as “unit session percentage”). The single highest-leverage number in the account: a CVR improvement makes every campaign and every keyword cheaper simultaneously.

AMC (Amazon Marketing Cloud) — Amazon’s clean-room analytics environment where you can query event-level ad data across Sponsored Ads and DSP with SQL. This is where you answer questions standard reports can’t, like true new-to-brand overlap between campaign types — see our Amazon Marketing Cloud guide for what it’s realistically good for.

DSP (Demand-Side Platform) — Amazon’s programmatic display and video buying platform, which targets audiences on and off Amazon rather than keywords. Managed-service access historically required ~$10K+/month commitments; it earns its keep for retargeting and category conquest once Sponsored Products are already efficient.

Sponsored Products / Sponsored Brands / Sponsored Display — Amazon’s three self-service ad types. Sponsored Products are keyword- and product-targeted ads that look like organic results and carry most accounts’ spend; Sponsored Brands are the banner and video units reserved for Brand Registered sellers; Sponsored Display targets audiences and retargets shoppers on and off Amazon without requiring DSP budgets.

Search term vs. keyword — The keyword is what you bid on; the search term is what the shopper actually typed. The gap between them — visible in the Search Term Report — is where broad-match budgets go to die, and harvesting that report weekly is the baseline discipline of competent PPC management.

Negative keyword — A term you explicitly block your ads from matching. The unglamorous half of keyword strategy: most accounts we audit have thousands of dollars of monthly spend on search terms that a one-time negative list would have eliminated.

Impression share / Top-of-Search IS — The percentage of available impressions your ad captured, and specifically the share in the premium first-row placement. Falling top-of-search share on your hero keyword is often the earliest visible sign a competitor raised bids on you.

Placement modifiers — Percentage bid boosts applied by placement (top of search, product pages, rest of search). Because top-of-search can convert at 2–3x the rate of product-page placements, placement data — not keyword-level averages — should drive bid strategy.

Operations and Fulfillment

FBA (Fulfillment by Amazon) — You ship inventory to Amazon’s warehouses; Amazon stores, picks, packs, ships, and handles customer service, and your offers get the Prime badge. In exchange you pay fulfillment and storage fees and play by Amazon’s inventory rules.

FBM (Fulfilled by Merchant) — You ship orders yourself from your own warehouse or 3PL. Lower Amazon fees, full inventory control, but generally no Prime badge and a Buy Box disadvantage; the trade-offs are mapped in our FBA vs FBM comparison.

SFP (Seller Fulfilled Prime) — FBM with the Prime badge, earned by meeting brutal delivery-speed and on-time metrics (including weekend operations) during a trial period. Powerful for oversized or slow-turning products; unforgiving if your logistics slip.

IPI (Inventory Performance Index) — Amazon’s 0–1,000 score for how well you manage FBA inventory, driven by excess inventory, sell-through rate, stranded inventory, and in-stock rate. It matters because it gates your FBA capacity limits.

Capacity limits — The maximum inventory volume (cubic feet) Amazon will let you hold in FBA, set monthly per storage type and influenced by IPI and sales velocity. Hitting the ceiling before Q4 is one of the most expensive planning failures on the platform.

AWD (Amazon Warehousing & Distribution) — Amazon’s upstream bulk-storage network that auto-replenishes FBA. Cheaper per-cubic-foot than FBA storage, exempt from some capacity constraints, and increasingly Amazon’s preferred answer to “where do I hold my container of goods.”

3PL (Third-Party Logistics provider) — An outside warehouse that stores and ships your inventory. Most brands over ~$1M use one as a buffer between the factory and FBA, so a capacity cut or Q4 storage-fee spike doesn’t dictate their purchasing.

ASN (Advanced Shipment Notification) — The shipment-level data you (or your supplier) transmit before goods arrive — contents, quantities, carton details. In Vendor Central, ASN accuracy failures are a classic chargeback source; in FBA, the equivalent shipping-plan discrepancies trigger investigations and delays.

Stranded inventory — Units physically in FBA with no active listing to sell against, usually caused by listing suppression, pricing errors, or a broken parentage. It accrues storage fees while earning nothing, and it drags your IPI.

Reimbursements — Money Amazon owes you for inventory it lost, damaged, or mis-received, and for customer returns never actually returned. Amazon auto-reimburses some of it; the rest requires systematic claims, covered in our guide to FBA reimbursements.

Catalog and Content

ASIN (Amazon Standard Identification Number) — Amazon’s ten-character identifier for a product page. One ASIN, one detail page, shared by every seller offering that product — which is why catalog control matters more than most brands realize.

SKU — Your internal identifier for an offer, unique to your account. Multiple SKUs can point to one ASIN (e.g., FBA and FBM offers of the same product), which is a feature during Q4 capacity crunches and a source of confusion in every P&L meeting.

Parentage (parent/child variations) — The structure linking size and color variants under one parent ASIN so they share a detail page and pool reviews. Broken or abusive parentage is a common cause of suppressed listings and, when done to manipulate reviews, a policy violation Amazon actively hunts.

A+ Content — The modular image-and-text section below the bullets, available to Brand Registered sellers, including Premium A+ with video and comparison tables. Done properly it lifts conversion measurably; done as a logo banner it’s wasted real estate — see our A+ Content guide.

Brand Story — The scrollable brand carousel that sits above A+ Content, cross-linking your catalog on every detail page. Its quiet job is defensive: it pushes competitor ad placements further down your own listing.

Listing suppression — Amazon hiding your detail page from search because of a policy or data problem (missing attributes, pricing alerts, restricted claims). Revenue stops immediately, and the fix path depends entirely on the suppression reason.

Flat file — The Excel/tab-delimited templates for bulk catalog operations. Still the only reliable way to fix certain attribute and parentage problems that the Seller Central UI will not touch.

BSR (Best Sellers Rank) — The sales-velocity rank Amazon assigns each product within its categories, updated roughly hourly and weighted heavily toward recent sales. Useful as a relative trend line and for competitor research in tools like Keepa and SmartScout; useless as an absolute number without category context.

Session — One visit to your detail page within a 24-hour window, reported in Business Reports. Sessions times unit session percentage is your unit sales — which means every revenue problem decomposes into a traffic problem, a conversion problem, or both, and that decomposition should be the first step of any diagnosis.

Manage Your Experiments — Amazon’s native A/B testing tool for Brand Registered sellers, covering titles, main images, bullets, and A+ Content. The only split-testing method that uses Amazon’s real traffic with proper randomization, though it needs high-traffic ASINs and 8–10 weeks to reach significance.

Account Health

AHR (Account Health Rating) — The 0–1,000 score summarizing your policy compliance, visible on the Account Health page. It’s a weather report, not a shield: a “Healthy” green score does not prevent enforcement on a fresh critical violation.

ODR (Order Defect Rate) — Negative feedback + A-to-z claims + chargebacks, divided by orders, over a rolling 60 days. Must stay under 1%; crossing it risks account deactivation regardless of how good everything else looks.

LSR (Late Shipment Rate) — Orders confirmed as shipped after the expected ship date, for seller-fulfilled orders. Amazon’s threshold is 4%, and repeated breaches suspend your FBM offers even if FBA sales are fine.

VTR (Valid Tracking Rate) — Percentage of FBM shipments with valid, scanning tracking numbers. The bar is 95%; cheap untracked shipping methods on low-value items are the usual way sellers stumble into a VTR problem.

POA (Plan of Action) — The structured appeal document Amazon expects after a suspension or ASIN takedown: root cause, immediate corrective actions, and long-term preventive measures. Amazon’s investigators pattern-match; a POA that blames the buyer or the courier gets rejected on read one.

Section 3 — The clause of Amazon’s Business Solutions Agreement covering account deactivation for policy violations. When a suspension notice cites “Section 3,” you’re in formal enforcement territory and the quality of your first appeal matters enormously.

A-to-z Guarantee claim — A buyer’s formal claim against a seller-fulfilled order for non-delivery or item problems, adjudicated by Amazon and counted against your ODR even when you refund promptly. Winning them requires tracking data and fast responses; ignoring them for 48 hours forfeits the case.

Voice of the Customer — The Seller Central dashboard aggregating returns, refund comments, and buyer contacts into a CX health rating per SKU. It surfaces product-quality problems weeks before they show up as one-star reviews, which makes it the most underused early-warning system on the platform.

Chargeback (Vendor Central) — In the Vendor Central world, a chargeback is not a credit-card dispute but an operational penalty Amazon deducts for logistics infractions: late ASNs, wrong carton labels, missed appointment windows. They’re disputable, and systematically disputing them recovers real money — one of our engagements recovered $180K in Vendor Central chargebacks.

Amazon Programs

Brand Registry — Amazon’s program for trademark owners, and the gateway to nearly every brand tool: A+ Content, Brand Story, Sponsored Brands, Brand Analytics, storefronts, Vine, and IP-protection reporting. If you own the brand and sell it on Amazon, enrollment is not optional in any practical sense.

Vine — Amazon’s invitation-only review program: you give units to vetted reviewers, they leave honest (not guaranteed-positive) reviews. It’s the only compliant way to seed reviews on a new ASIN, and it’s covered in depth in our Vine program guide.

Transparency — Amazon’s serialization program: every unit carries a unique 2D code Amazon scans at fulfillment, so counterfeit units physically cannot be fulfilled. Strong medicine for brands with a real counterfeiting problem; a per-unit cost and labeling obligation for everyone else.

Project Zero — Grants qualifying Brand Registered sellers self-service power to remove counterfeit listings directly, backed by Amazon’s automated protections. The removal privilege is audited — abuse it against legitimate resellers and you lose it.

Subscribe & Save — Amazon’s subscription program for replenishable products, funded partly by seller-paid discounts. For consumables, a growing S&S base is the closest thing Amazon offers to recurring revenue and it stabilizes velocity through demand troughs.

Buy Box (Featured Offer) — The default add-to-cart offer when multiple sellers share an ASIN, awarded on price, fulfillment method, and seller metrics. Losing it on your own brand’s listings usually means an unauthorized seller undercutting you — a distribution problem wearing a pricing costume.

Brand Analytics — Search-behavior data (Search Query Performance, Market Basket, demographics) available to Brand Registered sellers. Search Query Performance is the closest thing to ground truth on where you win and lose the click, and it should feed both SEO and PPC decisions.

Putting the Amazon Seller Glossary to Work

A glossary gets everyone speaking the same language; it doesn’t tell you which of these numbers is quietly wrong in your account. If your team can define TACoS but nobody can explain why it climbed four points this quarter, that’s a diagnosis problem — the kind we work through in a free account audit.