Marketplace seller glossary

Showing 20 of 20 terms.

A+ ContentEnhanced Brand Content

A+ Content is Amazon's enhanced product description feature, available to brand-registered sellers. It replaces the plain description with image and text modules.

Listing content

ACoSAdvertising Cost of Sale

ACoS is advertising spend divided by the revenue that advertising generated, expressed as a percentage. An ACoS of 25% means you spent $25 on ads for every $100 of ad-attributed sales.

Advertising

ASINAmazon Standard Identification Number

An ASIN is the ten-character alphanumeric code Amazon assigns to every product in its catalogue. It identifies the product page, not your particular offer on it.

Identifiers

Backend search terms

Backend search terms are a hidden keyword field Amazon indexes but shoppers never see. The limit is 250 bytes, and exceeding it can void the entire field rather than truncating the overflow.

Listing content

Break-even ACoS

Break-even ACoS is the advertising cost of sale at which an ad-driven sale produces zero profit. It is mathematically identical to your gross margin percentage.

Advertising

Buy BoxFeatured Offer

The Buy Box is the Add to Cart panel on an Amazon product page shared by multiple sellers. The seller who wins it receives the overwhelming majority of that page's sales.

Marketplace search

COSMO

COSMO is Amazon's semantic search model, which interprets what a shopper is trying to accomplish rather than matching query text to listing text literally.

Marketplace search

FBAFulfilment by Amazon

FBA is Amazon's fulfilment service: you ship inventory to Amazon's warehouses, and Amazon picks, packs, ships and handles customer service for each order in exchange for a per-unit fee.

Fulfilment and fees

FBMFulfilled by Merchant

FBM means the seller stores, packs and ships their own orders rather than using Amazon's warehouses. Amazon still handles the transaction and charges a referral fee, but no fulfilment fee.

Fulfilment and fees

GTINUPC, EAN, Global Trade Item Number

A GTIN is a globally unique product barcode number. UPC (12 digits, North America) and EAN (13 digits, Europe) are both types of GTIN, and most marketplaces require one to create a listing.

Identifiers

Item specifics

Item specifics are eBay's structured product attributes — brand, model, size, colour, material, MPN. They drive Best Match ranking and the sidebar filters buyers use to narrow results.

Marketplace search

Listing suppression

Listing suppression is when a marketplace hides a product from search results while leaving the page technically live. The listing exists, receives no traffic, and often generates no error message.

Listing content

Main imageHero image

The main image is the first product photo shown in search results and at the top of the listing. On Amazon it must be on a pure white background (RGB 255, 255, 255) with the product filling at least 85% of the frame.

Listing content

Organic rank

Organic rank is a listing's unpaid position in marketplace search results for a given query. It is driven mainly by relevance and sales velocity, not by advertising spend directly.

Marketplace search

Referral fee

A referral fee is the percentage of the total sale price a marketplace takes as commission. On Amazon it is typically 15%, though it varies by category from 8% to 45% and is subject to a minimum per item.

Fulfilment and fees

ROASReturn on Ad Spend

ROAS is revenue divided by advertising spend, expressed as a ratio. A ROAS of 4 means $4 of revenue for every $1 spent. It is the reciprocal of ACoS.

Advertising

Rufus

Rufus is Amazon's AI shopping assistant. It reads listing content and answers shopper questions conversationally, which means your listing can be surfaced without the shopper ever seeing a search results page.

Marketplace search

Size tier

Size tier is the category Amazon assigns a product based on its packaged dimensions and weight, and it determines the FBA fulfilment fee. Dimensions are checked before weight.

Fulfilment and fees

SKUStock Keeping Unit

A SKU is your own internal code for a specific product variant. Unlike an ASIN or GTIN, it is chosen by you and does not need to be unique outside your own catalogue.

Identifiers

TACoSTotal Advertising Cost of Sale

TACoS is advertising spend divided by total revenue — organic and ad-driven combined — rather than by ad-attributed revenue alone. It shows whether advertising is growing the business overall.

Advertising