Amazon advertising metrics glossary

What are the key Amazon advertising metrics?

The core Amazon advertising metrics are ACoS (ad spend divided by attributed sales), ROAS (its inverse), TACoS (ad spend divided by total sales), CPC and CPM (what you pay per click or per thousand impressions), CTR and conversion rate (how often impressions become clicks and clicks become orders), and the attribution window that decides which sales count. Judge all of them against your own margin, not a borrowed benchmark.

Published by Marketplace Ad Pros. Definitions follow Amazon Ads documentation; formulas are shown as ratios.

Last updated: October 14, 2026

Quick reference

Every ratio here is a ratio first: an ACoS of 0.25 is 25%. If a tool shows "25" and another shows "0.25", they agree.

Glossary

ACoS (Advertising Cost of Sales)

ACoS is ad spend divided by the sales those ads are credited with, inside Amazon's attribution window. It measures how efficiently the advertising itself converts spend into attributed revenue. Lower is more efficient, but a low ACoS can also mean you are under-investing in discovery.

ACoS = ad spend / ad-attributed sales

TACoS (Total Advertising Cost of Sales)

TACoS is ad spend divided by total sales, advertised and organic together. It shows what advertising costs the whole business rather than the ads alone, and it needs Seller Central or Vendor Central sales data because the advertising reports do not contain organic sales.

TACoS = ad spend / total sales

ROAS (Return on Ad Spend)

ROAS is ad-attributed sales divided by ad spend, the inverse of ACoS. A ROAS of 4 means four dollars of attributed sales per dollar spent, which is the same thing as a 25% ACoS. Amazon's DSP and most off-Amazon channels report ROAS, while Sponsored ads teams tend to talk in ACoS.

ROAS = ad-attributed sales / ad spend = 1 / ACoS

CPC (Cost per Click)

CPC is what you actually paid for a click, averaged over a period. It is not your bid: your bid is the maximum you are willing to pay, and the charged price depends on the auction. Sponsored Products, Sponsored Brands and many display ad campaigns are billed per click.

CPC = ad spend / clicks

CPM (Cost per Mille)

CPM is the cost of one thousand ad impressions; mille is Latin for thousand. In Amazon advertising it is the billing basis for Amazon DSP, streaming TV and some Sponsored Display and Sponsored Brands video campaigns. Compare CPM-billed campaigns on outcomes such as ROAS, not on CPM alone.

CPM = ad spend / impressions x 1,000

vCPM (Viewable Cost per Mille)

vCPM is the cost of one thousand viewable impressions, meaning impressions that met a viewability standard rather than every ad served. Sponsored Display campaigns optimized for reach can bill on vCPM. It is usually higher than CPM because fewer impressions qualify.

vCPM = ad spend / viewable impressions x 1,000

Impressions

An impression is one display of your ad to a shopper. Impressions measure reach and visibility, not interest. A sudden drop usually points to lost auctions (bids or budget), a listing that lost the Buy Box or went out of stock, or a paused campaign.

CTR (Click-Through Rate)

CTR is the share of impressions that became clicks. It reflects how relevant and appealing the ad, main image, title, price and review count look next to competitors on the same results page. A low CTR on a high-impression keyword often means the keyword is a poor match.

CTR = clicks / impressions

CVR (Conversion Rate)

Conversion rate is the share of ad clicks that led to an attributed order. It is driven mostly by the detail page: price, reviews, images, and whether the product matches what the shopper searched for. Amazon's Business Reports use a different conversion rate, unit session percentage, based on sessions.

CVR = attributed orders / clicks

Ad-attributed sales

Ad-attributed sales are the sales Amazon credits to an ad because the shopper clicked or viewed it within the attribution window before purchasing. They include purchases of other products from the same brand (halo sales), and they are a subset of total sales, which also contains organic orders.

Attribution window

The attribution window is how long after an ad interaction a purchase is still credited to the ad. By default, Sponsored Products credits sales within 7 days of a click for sellers and 14 days for vendors, while Sponsored Brands and display ads use 14 days. The Ads API also offers 1, 7, 14 and 30 day columns, so check which window a tool reports.

Halo sales

Halo sales are attributed purchases of a different product from the same brand than the one advertised. Amazon includes them in attributed sales and reports them separately as other-SKU sales, so an ad can look profitable on brand-wide sales while the advertised product itself barely converts.

NTB (New-to-Brand)

New-to-brand orders are attributed orders from shoppers who had not bought from your brand on Amazon in the previous 12 months. NTB metrics are available for Sponsored Brands, Sponsored Display and Amazon DSP, and require Brand Registry. They separate customer acquisition from repeat purchasing.

NTB % = new-to-brand orders / attributed orders

DPV (Detail Page Views)

Detail page views count visits to your product page that Amazon attributes to an ad, including views from impressions on Sponsored Display and DSP. DPV is the upper-funnel success measure for awareness campaigns, where clicks and attributed sales understate the effect.

Top-of-search impression share

Top-of-search impression share is the percentage of eligible top-of-search impressions your campaign won for a keyword or target. Amazon reports it for Sponsored Products and Sponsored Brands. It is the closest native measure of how visible you are at the most valuable placement.

Suggested bid

A suggested bid is Amazon's estimate of a bid likely to win impressions, based on recent winning bids for similar ads. It describes what the auction has been clearing at, not what a click is worth to you. Compare it with your own maximum profitable CPC before accepting it.

Break-even ACoS

Break-even ACoS is the ACoS at which ad-attributed sales exactly cover the ad spend after product cost, Amazon fees and shipping. It equals your pre-advertising profit margin. Above it, each attributed sale loses money; below it, the ads are profitable on attributed sales alone.

Break-even ACoS = (price - COGS - Amazon fees - other unit costs) / price

Maximum profitable CPC

Maximum profitable CPC is the highest cost per click you can pay and still hit your target ACoS, given your conversion rate and price. It is the number to compare against Amazon's suggested bid. It moves whenever price, conversion rate or margin changes.

Max CPC = target ACoS x average order value x CVR

Organic sales

Organic sales are the orders Amazon does not attribute to any ad. They are total sales minus ad-attributed sales. Advertising can lift organic sales indirectly through sales velocity and ranking, which is why TACoS and organic share are watched alongside ACoS.

Organic sales = total sales - ad-attributed sales

Wasted ad spend

Wasted ad spend is spend on clicks, search terms or targets that produced no attributed orders over a meaningful sample. It is not a metric Amazon reports, so you find it in the search term report. Judge each term against your own conversion rate before negating it.

How these metrics fit together

Read them as a chain. Impressions become clicks at your CTR, clicks become orders at your conversion rate, and each click costs your CPC. Those three numbers determine ACoS:

ACoS = CPC / (CVR x average order value)

So an ACoS problem is always a CPC problem, a conversion problem, or a price problem, and the metrics upstream tell you which. TACoS then asks the business question ACoS cannot: is advertising growing total sales, or just claiming credit for sales you would have made anyway? The full method, and the six ways a naive TACoS calculation goes wrong, is in how to calculate TACoS on Amazon.

To turn margin into targets, use the break-even ACoS calculator and the PPC bid calculator. Both run in your browser.

Where to see these metrics together

The Amazon Ads console reports the advertising metrics; Seller Central and Vendor Central report total sales. No native screen puts TACoS, organic share and margin in one view, because the two halves live in different systems. Marketplace Ad Pros connects Amazon Ads and Selling Partner data to Claude and ChatGPT through an MCP server, read-only by default, from $10/week, so you can ask for any metric on this page across both halves in plain language. See what Marketplace Ad Pros is, or connect your Amazon accounts free and ask for your own TACoS.

Frequently asked questions

What does CPM mean in Amazon advertising?

CPM means cost per mille, the price of one thousand ad impressions. On Amazon it is the billing basis for Amazon DSP, streaming TV ads and some Sponsored Display and Sponsored Brands video campaigns, while Sponsored Products are billed per click. Divide spend by impressions and multiply by 1,000 to get it.

What is the difference between ACoS and ROAS?

They are the same measurement turned upside down. ACoS is ad spend divided by attributed sales and ROAS is attributed sales divided by ad spend, so ROAS equals 1 divided by ACoS. A 25% ACoS is a ROAS of 4.

What is the difference between ACoS and TACoS?

The denominator. ACoS divides ad spend by ad-attributed sales, so it measures the ads alone. TACoS divides ad spend by total sales, ad and organic, so it measures what advertising costs the business. TACoS needs Seller Central or Vendor Central data, which is why many tools can only show ACoS.

What is a good ACoS on Amazon?

There is no universal good ACoS. The useful benchmark is your own break-even ACoS, which equals your profit margin before advertising. A launch can justify running above break-even for a period; a mature product usually should not. Compare category averages only after you know your own margin.

Why do Amazon Ads sales not match Seller Central sales?

They measure different things. Ads reports show attributed sales, credited to an ad within the attribution window and including halo sales of other products from the same brand, while Seller Central shows every order. Recent days also keep changing as late attributed orders arrive, so compare settled periods.

Should I use Amazon's suggested bid?

Use it as a description of the market, not a target. A suggested bid reflects what similar winning bids have been clearing at. Your maximum profitable CPC depends on your price, conversion rate and margin, so calculate it and bid the lower of the two unless you are deliberately buying rank.

Related guides

• How to calculate TACoS on Amazon: the correct formula
• How to find wasted ad spend on Amazon: a 5-check audit
• Amazon Ads review 2026: self-serve strengths, costs and risks
• Amazon Prime Day 2026 ad benchmarks
• Best Amazon advertising reporting and analytics tools in 2026

Sources

1. Amazon Ads -- Sponsored Products
2. Amazon Ads -- Sponsored Brands
3. Amazon Ads -- display ads (formerly Sponsored Display)
4. Amazon Ads -- how suggested bids are calculated
5. Amazon Ads -- dynamic bidding for Sponsored Products
6. Amazon Ads -- basics of Amazon Attribution
7. Intentwise -- how Amazon attributes ad sales (default attribution windows)