Amazon and Walmart run on their own vocabulary, and half of it is acronyms. Here are 47 terms sellers actually run into in 2026, each with a one-line definition first and the practical meaning after.
The terms that matter most: ACoS is ad spend divided by ad sales; TACoS is ad spend divided by total sales; the Buy Box (Featured Offer) is the offer attached to Add to Cart; FBA means Amazon stores and ships your orders; and WFS is Walmart's equivalent. Fees and thresholds change, so confirm current numbers in Seller Central or Seller Center.
What is Amazon A+ Content?
A+ Content is enhanced product-description content, such as image modules, comparison charts and formatted text, that brand-registered sellers add to a listing in place of the plain product description.
Use it to answer objections the bullets cannot and to cross-sell through comparison charts. Don't rely on A+ text for keyword indexing; keep key terms in the title, bullets and backend. See the A+ Content guide.
What is Amazon's Account Health Rating?
Account Health Rating (AHR) is Amazon's score for how well a seller follows its selling policies, based on unresolved violations. It appears on the Account Health dashboard in Seller Central, on a scale from 0 to 1,000.
Higher is better, and a low enough score puts the account at risk of deactivation; check the dashboard for current bands. Resolve violations quickly instead of letting them stack. If it has gone wrong, see our account reinstatement service.
What is ACoS?
ACoS (advertising cost of sales) is ad spend divided by the sales those ads generated, shown as a percentage. Spending $30 to drive $100 in ad-attributed sales is a 30% ACoS.
ACoS measures ad efficiency, not business health: a low ACoS can just mean you only bid on your own brand name. Judge it against your break-even ACoS and next to TACoS. See how to lower ACoS without killing sales.
Formula: ACoS = ad spend ÷ ad-attributed sales × 100
What is the aged inventory surcharge?
The aged inventory surcharge is a monthly FBA fee Amazon charges, on top of regular storage fees, for units that have sat in its fulfillment centers longer than a set age threshold.
The rate climbs as stock ages. Clear it before the next threshold with promotions, ads, removal or liquidation, then fix the forecast. Thresholds and rates change; check Amazon's fee page. See the inventory management guide.
What is Amazon DSP?
Amazon DSP (demand-side platform) is Amazon's programmatic advertising platform for buying display, video and audio ads on Amazon and across third-party sites and apps, targeted with Amazon's shopping audiences.
Unlike Sponsored ads, DSP is open to non-sellers and is usually bought on impressions (CPM) rather than clicks. Access models and minimums have changed over time; check current terms.
What is Amazon Marketing Cloud (AMC)?
Amazon Marketing Cloud (AMC) is Amazon's privacy-safe clean room where advertisers query pseudonymized Amazon Ads event data to analyze customer journeys, measure how ad types work together and build custom audiences.
AMC returns aggregated results only, never individual shopper data. Typical uses are path-to-purchase analysis, ad-type overlap and new-to-brand audiences. It usually takes SQL or templates to use well, and pays off most for brands spending across several ad types.
What is Amazon Vine?
Amazon Vine is an invitation-based program in which Amazon gives free units of a brand-registered seller's product to trusted reviewers, called Vine Voices, who post honest reviews labeled as Vine reviews.
It is a compliant way to get early reviews, but they are not guaranteed to be positive. Fees and eligibility have changed over time, so check Seller Central. See our Amazon Vine guide and how to get more reviews.
What is an ASIN?
An ASIN (Amazon Standard Identification Number) is the unique 10-character alphanumeric ID Amazon assigns to a product in its catalog. For books, the ASIN is the ISBN-10.
Every detail page is tied to one ASIN, and every seller of that exact product shares it, which is why duplicate listings break policy. You will find it in reports and in the product URL after "/dp/".
What are backend search terms on Amazon?
Backend search terms are hidden keywords entered in a listing's Search Terms field in Seller Central. Shoppers never see them, but Amazon uses them for search indexing. The US limit is 249 bytes.
Use them for synonyms and alternate spellings that don't fit the visible copy. Skip words already in the title, brand names, ASINs and claims like "best"; going over the limit can stop the field indexing. Check yours with the free backend keywords checker.
What is Amazon Brand Analytics?
Amazon Brand Analytics is a Seller Central dashboard for brand owners enrolled in Brand Registry. It reports search and customer behavior data, including top search terms, Search Query Performance, market basket and repeat purchase behavior.
The Top Search Terms view shows search frequency rank and the most-clicked ASINs per query, useful for keyword research and competitor tracking. It is one of the most valuable free benefits of Brand Registry.
What is Amazon Brand Registry?
Amazon Brand Registry is Amazon's program for trademark owners. It gives the registered brand more control over its listings, stronger protection tools and access to brand-only features like A+ Content, Brand Stores and Sponsored Brands.
Enrollment generally requires a registered trademark, or in many cases a pending application in an eligible office; check Amazon's current rules. For private label it is close to mandatory. See our Brand Registry guide and USPTO trademark service.
What is an Amazon Brand Store?
An Amazon Brand Store is a free, multi-page storefront on Amazon with its own URL. Brand-registered sellers use it to show their full catalog and brand story in one place.
It works best as a landing page for Sponsored Brands and external traffic, where shoppers see only your products. See our Brand Store guide.
What is break-even ACoS?
Break-even ACoS is the highest ACoS at which an ad-driven sale still covers its costs. It equals your profit per unit before advertising, divided by the selling price.
Hypothetical example: a $30 product with $18 of landed cost and Amazon fees leaves $12 before ads, so break-even ACoS is 40%. Above that, each ad sale loses money. Work it out per unit with our free FBA calculator.
Formula: Break-even ACoS = (price − product cost − Amazon fees − other variable costs) ÷ price × 100
What is the Amazon Buy Box (Featured Offer)?
The Buy Box, which Amazon now calls the Featured Offer, is the offer shown with the Add to Cart and Buy Now buttons on a product page. When several sellers offer the same product, Amazon chooses which one is featured.
Amazon weighs price including shipping, delivery speed, fulfillment method, stock and seller performance. For private label, be the only seller: lose it to a hijacker and your ads generally stop serving. See how to win the Buy Box.
What are FBA capacity limits?
FBA capacity limits are the maximum amount of inventory, measured in cubic feet, that Amazon lets a seller store in or ship to its fulfillment centers, set monthly by storage type.
Amazon bases them on factors like sales history, forecast, inventory performance and its own network capacity. Plan inbound shipments around them, especially before Q4. See the 3,000 units/month playbook.
What is CPC on Amazon?
CPC (cost per click) is what you pay each time a shopper clicks your ad. Amazon sets it through an auction, so the actual CPC is typically at or below your bid.
Placement adjustments and dynamic bidding can push it above your base bid. CPC only means something next to conversion rate: a $2 click converting at 20% costs $10 per order; a $1 click converting at 5% costs $20.
Formula: CPC = ad spend ÷ clicks
What is CTR?
CTR (click-through rate) is the percentage of ad impressions that turn into a click. It shows how compelling your main image, title, price, rating and badges look next to competitors.
Low CTR on a relevant keyword is usually a creative or offer problem, so test the main image and price before touching bids. Low CTR on an irrelevant keyword is a targeting problem. See the listing optimization guide.
Formula: CTR = clicks ÷ impressions × 100
What is conversion rate (CVR) and Unit Session Percentage?
Conversion rate (CVR) is the share of clicks or visits that turn into orders. Amazon's Business Reports version is Unit Session Percentage: units ordered divided by sessions.
Unit Session Percentage counts units, so multi-unit orders can push it above your order conversion rate. Low conversion usually traces to price, images, reviews or rating; see why a 4.1-star product struggles.
Formula: Ad CVR = orders ÷ clicks × 100 | Unit Session Percentage = units ordered ÷ sessions × 100
What is FBA (Fulfillment by Amazon)?
Fulfillment by Amazon (FBA) is Amazon's program in which sellers send inventory to Amazon's fulfillment centers, and Amazon stores, picks, packs and ships the orders and handles customer service and returns, for a fee.
FBA offers are Prime-eligible, which usually lifts conversion. The trade-off is fees and inventory rules. See Amazon FBA fees explained, FBA vs FBM and the free FBA calculator.
What is FBM (Fulfillment by Merchant)?
Fulfillment by Merchant (FBM), also called merchant-fulfilled, means the seller stores inventory and ships orders to customers directly or through a 3PL, instead of using Amazon's fulfillment network.
FBM avoids FBA fees and capacity limits but puts shipping speed, returns and service on you, and isn't Prime-eligible by default. It suits oversized or slow-moving products and works as a stockout backup. Compare in the FBA vs FBM guide.
What is an FNSKU?
An FNSKU (Fulfillment Network SKU) is the Amazon-assigned barcode that identifies a specific seller's units in Amazon's fulfillment centers, so they are tracked separately from other sellers' units of the same ASIN.
It is the label you print from Seller Central for FBA units, typically starting with "X0". Whether you must use it or can use the manufacturer barcode depends on Amazon's current barcode rules, so check before shipping.
What is a GTIN or UPC?
A GTIN (Global Trade Item Number) is the standard number behind a product barcode; a UPC is the 12-digit GTIN format common in the US. Amazon and Walmart generally require one to create a new product listing.
Amazon checks GTINs against GS1 records, so buy them from GS1, not cheap resellers. Brand owners can often apply for a GTIN exemption, and Walmart has its own process. Check current rules on each marketplace.
What is an Amazon hijacker?
A hijacker is an unauthorized seller who adds an offer to your listing, often with counterfeit, lower-quality or unauthorized goods, to win the Buy Box and take your sales.
Document it with a test buy, send a cease-and-desist where appropriate, and report it through Brand Registry. A registered trademark and unique packaging make removal much easier. See the Brand Registry guide.
What is the Amazon inbound placement fee?
The inbound placement service fee is a per-unit FBA fee based on how many fulfillment center destinations you choose to split an inbound shipment across. Fewer destinations generally cost more per unit.
You pick the option when creating a shipment in Send to Amazon. Amazon's multi-location split usually lowers the fee but raises your freight cost, so compare total landed cost before confirming. See our FBA fees guide.
What is IPI (Inventory Performance Index)?
The Inventory Performance Index (IPI) is Amazon's score for how efficiently a seller manages FBA inventory. It reflects excess inventory, sell-through, stranded inventory and in-stock rate.
It runs from 0 to 1,000. Amazon has used IPI thresholds in storage and capacity rules, which change, so check the current threshold. Clear excess, fix stranded listings, keep winners in stock. See the inventory management guide.
What is the Walmart Listing Quality score?
Walmart's Listing Quality score is a Seller Center metric that rates how well your items are set up to be found and bought, based on content, discoverability, ratings and reviews, competitive price and shipping speed.
It flags the fixes that matter per item: missing attributes, weak images, uncompetitive price, slow shipping. Walmart adjusts the components, so check the dashboard. It is part of our Walmart Marketplace management.
What is the Amazon low-inventory-level fee?
The low-inventory-level fee is a per-unit FBA fee Amazon adds to standard-size items when your available stock stays low relative to customer demand. Some situations, such as new listings, are exempt.
The fix is reordering on lead time plus a safety buffer. It pulls the opposite way from the aged inventory surcharge, and thresholds and exemptions change, so check Seller Central. See Amazon FBA fees explained.
What are keyword match types on Amazon?
Match types control how closely a shopper's search must match your keyword for your ad to show: broad (loosest), phrase (search contains the phrase in order) and exact (the term or its close variants).
Close variants include plurals and misspellings. A standard structure uses broad and auto campaigns to discover terms, then moves proven converters into exact match while negating them in discovery campaigns.
What are negative keywords?
Negative keywords are terms you add to a campaign or ad group so your ads do not show for searches containing them. They stop spend on irrelevant or non-converting searches.
Amazon offers negative exact and negative phrase, plus negative product targeting. Pull the search term report weekly, find terms with clicks and no orders past a spend threshold, and negate them. See why most Amazon ad accounts fail.
What is ODR (Order Defect Rate)?
Order Defect Rate (ODR) is the percentage of a seller's orders over a 60-day window that received negative feedback, an A-to-z Guarantee claim or a credit card chargeback. Amazon's target is under 1%.
It is a core account health metric, and staying above target can lead to deactivation. Usual culprits: late or lost FBM shipments, misleading listings and slow customer service.
What is a parent-child variation on Amazon?
A parent-child variation groups related products, such as sizes, colors or pack counts, under a non-buyable parent ASIN, so shoppers choose options on one detail page while each child keeps its own ASIN.
Variations concentrate reviews and sales history on one page, which usually helps ranking. Only group genuine variants of the same item; merging unrelated products violates policy. See the listing optimization guide.
What is a Plan of Action (POA) on Amazon?
A Plan of Action (POA) is the written appeal a seller submits to Amazon to reinstate a suspended account or listing. It sets out the root cause, the corrective actions already taken and the preventive measures going forward.
Strong POAs are specific, factual and short, with no blame and no generic promises. Start with the free POA generator, read the reinstatement guide, or use our reinstatement service.
What is the Walmart Pro Seller badge?
The Walmart Pro Seller badge is a performance-based designation Walmart gives Marketplace sellers who consistently meet its standards across areas like delivery performance, customer experience and assortment.
There is no separate application; Walmart evaluates eligibility from performance data, and criteria change, so check Seller Center. The groundwork is covered in how to sell on Walmart.
What is a referral fee on Amazon and Walmart?
A referral fee is the commission a marketplace takes on each sale, calculated as a percentage of the total sales price. On Amazon and Walmart the rate varies by category.
On Amazon it is commonly around 15% in many categories, with per-item minimums in many. Walmart has no monthly subscription and category-based referral fees. Check each current fee schedule, and model it with our FBA calculator.
What is ROAS?
ROAS (return on ad spend) is ad-attributed sales divided by ad spend. $500 in ad sales from $100 of spend is a ROAS of 5, or 5:1. It is the inverse of ACoS.
Amazon Ads and Walmart Connect both report it, which makes it handy for comparing channels. Quick conversion: a 25% ACoS is a 4.0 ROAS; a 50% ACoS is 2.0. Like ACoS, it ignores organic sales and margin.
Formula: ROAS = ad-attributed sales ÷ ad spend = 1 ÷ ACoS (as a decimal)
What is Amazon Rufus?
Rufus is Amazon's generative AI shopping assistant in the Amazon app and website. It answers shoppers' questions and suggests products, drawing on listing content, reviews, Q&A and other catalog data.
Listings that clearly state use cases, specs, compatibility and who the product is for give it more to work with. Amazon doesn't publish how Rufus picks products, so treat "ranking factor" claims with caution. See the Rufus optimization guide.
What is Search Query Performance (SQP)?
Search Query Performance (SQP) is a Brand Analytics report showing, for each search term, total impressions, clicks, add-to-carts and purchases across Amazon, and your brand's share of each.
SQP combines organic and paid, so it is the most direct read on whether you are gaining or losing a query. It is available by brand or ASIN, weekly to quarterly. SQP rank tracking was part of the skin care turnaround in our case studies.
What is the search term report?
The search term report is an Amazon Ads report listing the actual shopper searches that triggered your ads, with impressions, clicks, spend, orders and sales for each term.
It is the raw material for negative keywords and new exact-match keywords. It shows paid activity only, so pair it with Search Query Performance for the full market picture. See the keyword research guide.
What is Seller Fulfilled Prime?
Seller Fulfilled Prime (SFP) is an Amazon program that lets sellers show the Prime badge on products they ship from their own warehouse or 3PL, provided they meet Amazon's strict delivery-speed and performance standards.
It involves a trial period and ongoing delivery and cancellation standards; miss them and the badge can go. Enrollment has opened and closed over the years, so check Seller Central for current availability.
What is a SKU on Amazon?
A SKU (stock keeping unit) is the seller-defined code that identifies a product in your own catalog and inventory. Unlike an ASIN, you create it, and one ASIN can have several of your SKUs.
Many sellers run FBA and FBM SKUs on one ASIN as a stockout backup. Use a readable pattern (brand, product, size, pack) and don't recycle old SKUs for new products.
What are Sponsored Brands?
Sponsored Brands are cost-per-click Amazon ads for brand-registered sellers that feature your logo, a custom headline and several products or a video. They commonly appear at the top of search results and other prominent placements.
Formats include product collection, store spotlight and video. They are strong for defending brand terms and sending traffic to your Brand Store. Formats change, so check the Amazon Ads console for what is currently available.
What is Sponsored Display?
Sponsored Display is Amazon's self-serve display ad type. It targets shoppers by product, category or audience, including retargeting people who viewed your product, and can serve on and off Amazon.
Private-label brands mostly use it for defensive targeting on their own detail pages and for retargeting shoppers who viewed but did not buy. Judge it on TACoS and new-to-brand data, not last-click ACoS alone.
What are Sponsored Products?
Sponsored Products are cost-per-click ads that promote individual product listings in Amazon search results and on product detail pages. They are the most widely used Amazon ad type and where most sellers start.
Campaigns use automatic targeting (Amazon picks queries) or manual targeting (you choose keywords or products), and your offer generally needs the Buy Box to serve. Walmart Connect sells a Sponsored Products format too. See our Amazon PPC management service.
What is TACoS?
TACoS (total advertising cost of sales) is ad spend divided by total sales, meaning ad-attributed plus organic. It shows how dependent the whole business is on advertising, not just how efficient individual ads are.
A falling TACoS while total sales grow usually means ads are building organic rank. A rising TACoS with flat sales means you are buying the same revenue at a higher price. The right level depends on margin and stage.
Formula: TACoS = ad spend ÷ total sales × 100
| Metric | Formula | What it tells you | Better when |
|---|---|---|---|
| ACoS | Ad spend ÷ ad sales | Efficiency of the ads themselves | Lower (down to a point) |
| TACoS | Ad spend ÷ total sales | How ad-dependent the business is | Stable or falling as sales grow |
| ROAS | Ad sales ÷ ad spend | Sales returned per ad dollar | Higher |
| Break-even ACoS | Pre-ad profit ÷ price | The ACoS ceiling before ads lose money | A limit, not a goal |
What is Walmart Connect?
Walmart Connect is Walmart's retail media business. For Marketplace sellers it runs Sponsored Products, with automatic and manual campaigns, plus formats such as Sponsored Brands and video ads across Walmart.com and the Walmart app.
Eligibility for brand-level and display formats varies and changes. The Amazon disciplines carry over: tight structure, weekly search term reviews, bids tied to margin. See our Walmart advertising service.
What is Walmart Seller Center?
Walmart Seller Center is the back-end portal where approved Walmart Marketplace sellers list items, manage orders, pricing and inventory, track performance and access programs like WFS and advertising.
It is Walmart's equivalent of Seller Central, but access is application-based: Walmart reviews your business details, tax ID, marketplace history and catalog first. See how to sell on Walmart and Walmart vs Amazon.
What is Walmart Fulfillment Services (WFS)?
Walmart Fulfillment Services (WFS) is Walmart's fulfillment program, similar to Amazon FBA. Sellers send inventory to Walmart's fulfillment centers, and Walmart stores, picks, packs and ships orders and handles returns.
WFS items can qualify for fast-shipping tags, which help conversion and the Walmart Buy Box. Fees are set by Walmart and change. Compare in WFS vs FBA.
How does Embarc Consulting use these metrics?
Embarc Consulting is a private-label-only agency for Amazon sellers founded in 2016, with 10+ years of Amazon account management and 120+ private-label brands managed. These terms are our weekly work: ad audits (wasted spend, negatives, bids toward target ACoS, budget pacing), SQP rank tracking, account health monitoring and readable weekly reporting.
Embarc Consulting also manages Walmart Marketplace accounts for private-label brands, using the same operator-led, AI-assisted weekly process. See our Amazon account management or Walmart Marketplace management pages, or see the anonymized case studies.