Amazon PPC Metrics: Formulas and Examples for 2026

Amazon PPC metrics are the numbers in your Amazon Ads reports that show how campaigns deliver, get clicked, convert and pay back. The ones that matter in 2026 are impressions, top-of-search impression share, CTR, CPC, conversion rate, ACOS, ROAS, TACoS, new-to-brand purchases, branded searches, and for DSP, reach, frequency and incrementality.

This guide gives the formula for each one, a worked example per group with the arithmetic, what changed in Amazon's reporting this year, and the decision each metric should trigger in the accounts we manage.

What Are Amazon PPC Metrics?

Amazon PPC metrics are the measures Amazon Ads reports for Sponsored Products, Sponsored Brands, display ads and DSP campaigns. Some are counts Amazon records directly (impressions, clicks, purchases, sales, cost). The rest are ratios you can rebuild from those counts.

That second point is the useful one. If you know the counts, you never have to trust a ratio you can't explain.

We sort them into six groups, in the order a shopper moves through them:

One identity ties the groups together. ACOS = CPC ÷ (conversion rate × average order value), so every efficiency problem is really an engagement or conversion problem underneath.

What Changed in Amazon Ads Metrics in 2026

Before the formulas, three changes this year affect almost every number in this guide. If your 2026 numbers look odd against 2025, start here.

1. Unified Reporting Renamed the Metrics

Amazon made unified reporting generally available on June 8, 2026. The legacy Sponsored ads and DSP report pages are read-only from December 17 and retire on December 31, 2026.

Amazon's unified reporting overview says measurement logic didn't change, but the names did. These are the renames that break spreadsheets:

Our guide to Amazon advertising reports covers building and migrating the reports themselves. This guide uses the new names, with the old ones where people still search for them.

2. View Attribution Changed on January 1

From January 1, 2026, vCPM Sponsored Brands, vCPM Sponsored Display (display ads) and DSP ads in the Amazon store credit views with a shopping-signal enhanced last-touch model and a shorter window. Click attribution didn't change.

The old count survives as "all views" metrics, such as Purchases (all views). They include every ad view within 14 days and live in unified reporting and the API.

So if view-through ROAS on a vCPM campaign dropped in January, compare Purchases with Purchases (all views) before you cut the budget. The gap is the methodology, not the campaign.

3. Attribution Windows Didn't Change

Windows still differ by ad type, which matters whenever you compare ACOS across campaigns. From Amazon's ad campaign attribution page and conversion attribution rules:

Recent days always look worse, because sales keep attributing for up to 14 days.

A 7-day Sponsored Products ACOS isn't directly comparable with a 14-day Sponsored Brands ACOS. Our Amazon attribution guide explains the windows in more depth.

Delivery Metrics: Impressions, Viewable Impressions, Top-of-Search Share

Delivery metrics tell you whether Amazon is showing your ads at all, and where. They are the first thing we check when sales drop, because nothing further down the funnel works without them.

1. Impressions

An impression is one time your ad is served. Amazon's performance metrics glossary reports it for each campaign and target.

Impressions rise with bids, budgets, relevance and broader targeting. Falling impressions with a steady bid usually mean a competitor outbid you, the campaign ran out of budget, or the product lost the Featured Offer.

2. Viewable Impressions and vCPM

A viewable impression meets the Media Rating Council standard: at least 50% of an image ad visible for one second, or 50% of a video for two seconds of play. Amazon reports it on campaigns billed per thousand viewable impressions (vCPM), such as display ads optimized for reach and Sponsored Brands with the "Grow brand impression share" goal.

Viewability rate = viewable impressions ÷ impressions vCPM = cost ÷ viewable impressions × 1,000

Example (illustrative): a vCPM Sponsored Brands campaign serves 400,000 impressions, 280,000 of them viewable, for $2,800. Viewability is 70% and vCPM is $10.00.

3. Top-of-Search Impression Share

Top-of-search impression share is the percentage of top-of-search impressions a campaign won out of those it was eligible for. Amazon's launch note says it covers Sponsored Products (first page only) and Sponsored Brands, with a 90-day lookback and up to 12 hours of delay.

Top-of-search IS = top-of-search impressions won ÷ top-of-search impressions eligible

If a campaign won 18,000 of 60,000 eligible top-of-search impressions, its share is 30%. In unified reporting it is available at campaign level only.

Impression share is the closest native signal to share of voice, but it only sees your own ads in auctions you entered. The lever is the top-of-search placement bid modifier.

Engagement Metrics: Clicks, CTR and CPC

Engagement metrics show whether shoppers pick your ad over the ones next to it, and what each pick costs.

1. Clicks and Click-Through Rate (CTR)

A click is one shopper clicking your ad. CTR is the share of impressions that got clicked.

CTR = clicks ÷ impressions × 100

CTR mostly measures relevance and the offer as it appears in the results: main image, title, price, rating, review count and the Prime badge. A low CTR on a relevant keyword is usually a listing problem, not a bidding one.

2. Cost per Click (CPC)

CPC is the average you paid per click. It is the auction price, so it moves with competition, placement and time of day.

CPC = cost ÷ clicks

Your bid is the most you are willing to pay, while CPC is what you actually paid. With bid adjustments and dynamic bidding, CPC can sit above the base bid on top-of-search clicks.

Worked Example: One Campaign Through Every Group

Take one Sponsored Products campaign over 30 days (illustrative numbers, seller account, 7-day attribution):

CTR is 1,000 ÷ 200,000 = 0.50%. CPC is $1,200 ÷ 1,000 = $1.20.

We carry this one campaign through the next two sections, so you can see how each ratio comes from the same counts.

Conversion Metrics: Purchases, Units, Conversion Rate and Sales

Conversion metrics tell you whether a click becomes an order. In unified reporting, "Purchases" is what most people still call orders.

Amazon removes payment failures and orders cancelled within 72 hours from purchases, and orders can take up to 12 hours to appear. That is one more reason never to judge today's numbers.

Conversion rate is where listings show up in ad data. Price, reviews, images, delivery speed and the Featured Offer all move it, and Sponsored Products only serve when your offer is the Featured Offer and in stock. Our Amazon conversion rate guide covers what moves it.

Watch halo sales too. Sponsored Products seller sales include other products you sell, and Sponsored Brands and display ads credit other products from your brand. Halo sales are real money, but they flatter the ad's own ASIN.

Efficiency Metrics: ACOS, ROAS, TACoS and CPA

Efficiency metrics compare spend with what it bought. These four are deep enough to have their own guides; here is how they relate on the same campaign.

ACOS and ROAS are the same measure turned upside down: ROAS = 100 ÷ ACOS. Amazon's DSP and most finance teams speak ROAS, while sponsored ads teams speak ACOS.

Neither means much without a margin. Amazon's own Ads Math guide calls ROAS a preliminary metric and works out break-even ROAS from gross margin.

Say the product carries a 35% margin before ad spend. Break-even ACOS is 35%, and break-even ROAS is 1 ÷ 0.35 = 2.86. At 34.8% ACOS, this campaign makes almost nothing on each ad sale.

Is that bad? Not if the TACoS of 8.7% is falling as organic sales grow. Our guides cover each side: break-even ACOS, how to reduce ACOS and TACoS targets by lifecycle stage.

The identity gives you the bid. Target CPC = target ACOS × conversion rate × AOV. For a 30% target: 0.30 × 0.10 × $34.50 = $1.04, so this campaign pays about 16 cents a click more than a 30% target allows.

Growth Metrics: New-to-Brand, Share of Voice and Branded Searches

Efficiency tells you whether spend paid back this month. Growth metrics tell you whether it built anything for next year.

1. New-to-Brand (NTB)

A purchase is new-to-brand when the shopper hasn't bought from your brand on Amazon in the previous 12 months. Amazon's new-to-brand page says these metrics are available for Sponsored Brands and display ads (and DSP), and not for Sponsored Products.

% purchases NTB = NTB purchases ÷ purchases × 100 Cost per NTB purchase = cost ÷ NTB purchases

Example (illustrative): a Sponsored Brands campaign spends $1,560 and drives 80 purchases, 52 of them new to brand. NTB share is 65% and each new customer cost $30.

Compare that $30 with what a customer is worth over a year, not with the first order's margin. Our new-to-brand metrics guide covers the full set, including NTB detail page views.

2. Share of Voice

Share of voice is your share of the search results slots for a keyword, organic and sponsored. Amazon doesn't report a page-level number, so you combine top-of-search impression share, search term impression share and Brand Analytics, or track the page directly.

Our Amazon share of voice guide has the formula and a worked example. The one rule we repeat here: measure it hourly on revenue keywords, because budgets run out in the evening.

3. Branded Searches

Branded searches count how often shoppers searched for your brand after an ad interaction. Amazon improved brand matching on October 1, 2025 to catch abbreviations and misspellings, so expect a step change in the trend from that date.

Branded search rate = branded searches ÷ impressions Cost per branded search = cost ÷ branded searches

In the Sponsored Brands example, 900 branded searches on 300,000 impressions is a 0.30% rate, at $1,560 ÷ 900 = $1.73 each. Like NTB, branded searches cover Sponsored Brands, display ads, Sponsored TV and DSP, not Sponsored Products.

Amazon's long-term sales metrics (US) go one step further. They estimate the sales a brand can expect over the next 12 months from new-to-brand engagements such as detail page views and branded searches.

DSP and AMC Metrics: Reach, Frequency, DPVR and Incrementality

DSP campaigns, now called Display, Video and Audio (DVA) campaigns, are bought on impressions. So their metrics start with people rather than clicks.

1. Reach and Frequency

Reach is the number of unique people (or households) who saw at least one ad. Frequency is how many times, on average, each of them saw it.

Frequency = impressions ÷ reach

1,200,000 impressions reaching 300,000 people is a frequency of 4.0. Amazon added dynamic, de-duplicated reach and frequency reporting at unBoxed in November 2025, cross-campaign breakdowns in February 2026 and cross-account reporting on April 2, 2026.

That matters because adding campaign-level reach double-counts people. Use the "Reach and frequency" template in unified reporting for any total across campaigns, and our DSP frequency capping guide to act on it.

2. Detail Page View Rate (DPVR) and eCPM

Detail page views (DPV) count visits to your product pages attributed to the ad. Amazon's DVA glossary defines DPVR as detail page views relative to impressions.

DPVR = detail page views ÷ impressions × 100 eCPM = cost ÷ impressions × 1,000

Example (illustrative): $9,600 buys 1,200,000 impressions and 6,000 detail page views. eCPM is $8.00 and DPVR is 0.50%, so each detail page view cost $1.60, a number you can set next to a Sponsored Products CPC.

Remember the 2026 base-metric change: in unified reporting, "Detail page views" includes halo, and "Detail page views (promoted)" is promoted products only. Our Amazon DSP reports guide covers the rest of the DSP set.

3. Incrementality

Incrementality is the share of results that wouldn't have happened without the ads. Attributed metrics can't show it, because they credit any purchase that followed an ad, including ones the shopper was going to make anyway.

You measure it by comparing an exposed group with a holdout group that was eligible but didn't see the ads:

Lift = (exposed conversion rate − holdout conversion rate) ÷ holdout conversion rate Incremental ROAS (iROAS) = incremental sales ÷ cost

Example (illustrative): 500,000 exposed households buy at 1.2% (6,000 purchases) and the holdout at 0.9%. Without ads, the exposed group would have made 4,500 purchases, so 1,500 are incremental, a 33% lift.

At a $40 order value that is $60,000 of incremental sales on $30,000 of spend, an iROAS of 2.0. The same campaign's attributed ROAS reads 8.0 ($240,000 ÷ $30,000), because it also credits the 4,500 purchases that would have happened anyway.

Amazon Marketing Cloud is where most advertisers run this analysis, and sponsored ads advertisers have had direct AMC access since September 2025. Our AMC paid features guide covers the advanced measurement options.

The Metric-to-Decision Map

A metric earns a place on a dashboard only if it changes a decision. This is the map we use to go from "something looks wrong" to the change we make.

The frequency threshold is our practitioner starting point, not an Amazon rule. Test it in your category.

Most of these checks run weekly. Our Amazon PPC audit puts them in order for a first pass on a new account, and the search terms report guide covers the CTR and conversion checks per term.

What Is a Good Number for Each Metric?

We don't quote universal benchmarks, because CTR, CPC and conversion rate vary several times over between categories and placements. A good number is one that clears your margin and beats your own trend.

Amazon now gives you category context directly. Its benchmarks reporting became generally available worldwide on May 18, 2026 for Brand Registry brands in 18 marketplaces.

It covers eight metrics: % of purchases new to brand, NTB purchase rate, cost per NTB purchase, CTR, CPC, video completion rate, cost per completed view and CPM. Compare against your category peers there before trusting any figure from a blog post, including ours.

For efficiency metrics, the benchmark is your own break-even. For growth metrics, it is the trend: NTB share, branded searches and TACoS should move the right way quarter over quarter.

Mistakes We See in Real Accounts

• Judging the last 7 days. Attribution runs up to 14 days. Targets with "zero sales" this week often convert by next Monday.

• Comparing 2025 and 2026 view-through ROAS directly. Use Purchases (all views) for like-for-like trends on vCPM and DSP campaigns.

• Averaging ratios. Average three campaigns' ACOS and you get a wrong number. Sum cost and sales first, then divide.

• Adding up campaign reach. The same people saw several campaigns. Use de-duplicated reach.

• Reading ACOS without CTR and conversion rate. ACOS tells you there is a problem; the inputs tell you which one.

• Treating attributed ROAS as incremental. Branded and retargeting campaigns post the best ROAS and often the lowest lift.

• Forgetting DSP base metrics now include halo. "Purchases" in unified reporting can read higher than the old DSP "Purchases" did.

How We Track Amazon PPC Metrics in Adbrew

Everything above works in the Amazon Ads console and a spreadsheet. It stops scaling when you manage several accounts, every ad type and a weekly report for a boss or a client.

Adbrew is an agentic retail media management platform for Amazon and Walmart, and the metrics in this guide are what it is built around:

• Dashboards across accounts. Custom dashboards combine ad, retail and profit data, so ACOS, TACoS and new-to-brand sit on one screen and share by link.

• Hourly data. Adbrew pulls Amazon Marketing Stream every hour, so CPC, spend and conversion rate are read while the day is running, not in tomorrow's file.

• Share of voice tracking. Digital Shelf Analytics tracks organic and sponsored SOV on your hero keywords, hourly or daily.

• AMC without SQL. Pre-built AMC reports for new-to-brand, overlap and path to conversion, refreshed daily.

• Rules you can read. Rules you set for bids, budgets, harvesting and negation act on these metrics with your thresholds and guardrails, and every change lands in Change History.

• Questions in plain English. Ask Adbrew Intelligence for "campaigns where CTR fell 30% week over week" and it builds the view. The same works from Claude or ChatGPT through the Adbrew MCP server.

This is a dashboard in Adbrew: account KPIs against the previous period across the top, with filters for placement, campaign label, campaign type, campaign and ad group.

Brands on Adbrew cut ACOS by 46% on average, and Seller Presto saves more than 250 hours of manual optimization a month. Much of that time used to go into building these numbers by hand.

Measure What Changes the Next Decision

You don't need every column Amazon offers. You need the counts behind each ratio, the 2026 names, the right attribution window, and a clear idea of what you will change when a number moves.

Want these metrics on one dashboard for every account, updated hourly? Book a demo and we'll build it on your data.