What do Amazon PPC terms like ACoS and TACoS mean? ACoS is ad spend divided by the sales your ads produced. TACoS is ad spend divided by all sales, organic included. RoAS is the inverse of ACoS. Break-even ACoS is the point where an ad sale stops making money. Below are 44 Amazon advertising terms, each with a plain definition and how we use it when we run an account.
By Andrew Morgans, founder of Marknology, selling on Amazon since 2011 | Updated September 2026
Most confusion in Amazon advertising comes from four ratios that sound alike. Here they are side by side.
| Metric | Formula | What it tells you | Watch out for |
|---|---|---|---|
| ACoS | Ad spend / attributed sales | Efficiency of the ads themselves | Ignores organic sales the ads helped create |
| RoAS | Attributed sales / ad spend | Same as ACoS, inverted | Easy to compare with other channels, same blind spots |
| TACoS | Ad spend / total sales | How dependent the business is on ads | Not reported by Amazon, so definitions vary |
| Break-even ACoS | Profit per unit before ads / price | The ACoS where an ad sale makes zero profit | Moves every time price, cost or fees change |
Go deeper in TACoS vs ACoS: which metric to manage to and what a good ACoS looks like.
Sources, checked September 25, 2026. Amazon Ads, ACoS guide.
The numbers every Amazon ads report is built on.
| Term | What it means | How we use it |
|---|---|---|
| ACoS (Advertising Cost of Sales) | Ad spend divided by the sales Amazon attributes to those ads, shown as a percentage. Example: $30 of spend that produces $100 of attributed sales is an ACoS of 30%. | Judge it against break-even ACoS for that product, never against a single account-wide number. |
| RoAS (Return on Ad Spend) | Attributed sales divided by ad spend. It is the inverse of ACoS: an ACoS of 25% is a RoAS of 4. | Same signal as ACoS, stated the other way round. Use whichever your finance team already reads. |
| TACoS (Total Advertising Cost of Sales) | Ad spend divided by total sales for the same products or account, including organic sales. It is an industry metric, not a column Amazon reports, so you calculate it yourself. | Watch the trend. Falling TACoS while sales grow usually means ads are lifting organic sales too. |
| Break-even ACoS | The ACoS at which an ad sale makes zero profit: the profit per unit before advertising, divided by the selling price. It changes whenever price, cost or fees change. | The anchor for every target. Below it, ads add profit on the first order; above it, you are buying growth on purpose. |
| Target ACoS | The ACoS you manage a campaign or product to. It can sit below break-even for profit or above it for a launch or ranking push. | Write the reason next to the number, so later decisions are measured against intent. |
| Attributed sales | Sales Amazon credits to an ad because the shopper clicked or viewed it within the attribution window. | Includes sales of other products from the same brand, reported separately as halo sales. |
| Attribution window | The number of days after a click or view in which a purchase is credited to the ad. Windows differ by ad type and by whether you are a seller or a vendor. | Compare ad types only on the same window, and let recent days settle before judging them. |
How shoppers move from seeing an ad to buying.
| Term | What it means | How we use it |
|---|---|---|
| Impressions | The number of times an ad was shown. | Low impressions on a relevant keyword usually point to a bid or relevance problem. |
| CTR (Click-Through Rate) | Clicks divided by impressions. | Mostly a test of the main image, title, price and review count against the rest of the page. |
| CPC (Cost per Click) | What you pay each time a shopper clicks the ad. In Amazon's auction you often pay less than your maximum bid. | Rising CPC with flat conversion is where profit quietly leaks. |
| Conversion rate | In ads reports, orders divided by clicks. In Business Reports, the organic version is called unit session percentage. | A listing problem shows up here first. Fix the page before raising bids. |
| Unit session percentage | Units ordered divided by sessions, from Seller Central Business Reports. It covers all traffic, not only ads. | Compare it with ads conversion to see whether ad traffic is better or worse quality than organic. |
| Impression share | The share of eligible impressions your ad won. Amazon reports top-of-search impression share for Sponsored Products. | Useful for branded and hero keywords where you want to own the top slot. |
| NTB (New-to-Brand) | Orders from shoppers who had not bought from your brand on Amazon in the previous twelve months. Amazon reports it for several ad types, including Sponsored Brands and Sponsored Display. | The clearest sign an ad is finding new customers rather than recapturing existing ones. |
The main places you can buy visibility on Amazon.
| Term | What it means | How we use it |
|---|---|---|
| Sponsored Products | Cost-per-click ads for a single product that appear in search results and on product pages. | Where most brands start and where most search spend sits. |
| Sponsored Brands | Ads with your logo, a headline and several products or a video, shown in search results. Requires Amazon Brand Registry. | Strongest once shoppers search for your brand or category by name. |
| Sponsored Display | Ads that target audiences or products, including retargeting shoppers who viewed your listings, on and off Amazon. | Behaves more like a demand channel than a search channel, so judge it with that in mind. |
| Sponsored TV | Self-service streaming TV ads sold through Amazon Ads. | Upper-funnel reach. Measure it on branded search and new-to-brand, not same-day sales. |
| Amazon DSP (Demand-Side Platform) | Amazon's programmatic platform for buying display, video and audio ads using Amazon audiences, on and off Amazon. | A different job with different economics from search ads. See our PPC vs DSP guide. |
| AMC (Amazon Marketing Cloud) | A clean-room analytics service where advertisers query event-level ad data with SQL to study paths to purchase and build audiences. | Answers questions standard reports cannot, such as how ad types work together. |
| Brand Store | A multi-page storefront on Amazon, at no extra cost, for brands in Brand Registry. Sponsored Brands ads can send traffic to it. | Useful for catalogs where shoppers compare several products. |
The Growth Diagnostic reviews your Amazon ads next to your product costs and fees, alongside your own site, TikTok Shop and other marketplaces, and ends with a 90-day roadmap. Its fee is credited to your first month if you continue with us.
See the Growth DiagnosticHow you tell Amazon who should see the ad.
| Term | What it means | How we use it |
|---|---|---|
| Keyword | A word or phrase you bid on so your ad can show for matching shopper searches. | Group keywords by intent: branded, category and competitor. |
| Search term | The exact text a shopper typed. One keyword can match many search terms. | The search term report is where you find new keywords and wasted spend. |
| Match types (broad, phrase, exact) | Rules for how closely a search must match your keyword. Exact is the tightest, phrase requires the phrase in order, broad is the loosest. | Broad and phrase find new terms; exact controls spend on proven ones. |
| Negative keyword | A keyword that stops your ad showing for searches that contain it. Available as negative exact and negative phrase. | Add negatives from real search term data, not guesses, or you can cut off sales you did not see. |
| Product targeting | Targeting specific ASINs or whole categories instead of keywords, so the ad appears on those product pages. | Good for placing a stronger offer next to a weaker competitor. |
| Automatic targeting | Campaigns where Amazon chooses targets from your listing. Split into close match, loose match, substitutes and complements. | A discovery tool. Harvest the winners into manual campaigns. |
| ASIN (Amazon Standard Identification Number) | Amazon's unique ten-character ID for a product in its catalog. | The unit you target, report and judge profit on. |
| Harvesting | Moving search terms that convert in auto or broad campaigns into exact-match campaigns, and adding them as negatives where they came from. | Keeps discovery and control in separate places so reports stay readable. |
The controls that decide what you pay and where you show.
| Term | What it means | How we use it |
|---|---|---|
| Bid | The most you are willing to pay for a click on a keyword or target. | Set bids from target ACoS and conversion rate, then adjust from data. |
| Dynamic bids down only | Amazon lowers your bid in real time when a click looks less likely to convert. | A sensible default for most campaigns. |
| Dynamic bids up and down | Amazon raises your bid when a click looks more likely to convert and lowers it when less likely. | Useful for proven terms. Watch CPC closely. |
| Fixed bids | Amazon uses your exact bid for every auction. | Gives control during tests and launches. |
| Placement adjustment | A percentage increase to your bid for a placement: top of search (first page), rest of search or product pages. | Raise it where the placement report shows better conversion, not everywhere. |
| Daily budget | The average amount a campaign can spend per day. Amazon can spend more on some days while staying within the monthly total. | A campaign that runs out of budget by midday is losing its best hours. |
| Portfolio | A folder that groups campaigns and can carry a shared budget cap. | Organize by brand, product line or goal so budgets match how you plan. |
| Dayparting | Changing bids or budgets by hour or day of week, through Amazon budget rules or third-party tools. | Only worth it when hourly data shows a clear pattern. |
Terms that connect ad reports to the P&L.
| Term | What it means | How we use it |
|---|---|---|
| Halo sales | Sales of other products from your brand that followed an ad click. Amazon reports them as other SKU or brand halo sales. | Count them when the whole catalog benefits, but do not let them hide a weak ad. |
| Incrementality | The sales that would not have happened without the ad. | Branded ads often score well on ACoS but low on incrementality. Test before cutting or scaling. |
| Branded vs non-branded | Searches that include your brand name versus generic or competitor searches. | Report them separately. Mixing them makes a weak account look healthy. |
| Cannibalization | When an ad takes credit for a sale you would have won organically anyway. | Most common on branded terms where you already rank first. |
| Share of voice | Your share of visible ad and organic positions for a set of keywords. | A market view. Useful alongside sales, not instead of it. |
| Lifetime value (LTV) | Profit from a customer over all their orders, not only the first. | Products with strong repeat purchase can justify an ACoS above break-even on the first order. |
| Contribution margin | Revenue minus product cost, Amazon fees, fulfillment and advertising for a product. | The number we use to decide which products get more ad budget. |
ACoS stands for Advertising Cost of Sales. It is ad spend divided by the sales Amazon attributes to those ads, shown as a percentage. An ACoS of 30% means you spent 30 cents on ads for every dollar of attributed sales.
TACoS stands for Total Advertising Cost of Sales. It is ad spend divided by all sales, including organic sales, for the same products or account. Amazon does not report it directly, so you calculate it from ads and sales data.
They measure the same thing from opposite directions. ACoS is spend divided by attributed sales, and RoAS is attributed sales divided by spend. An ACoS of 20% equals a RoAS of 5.
There is no single good ACoS. A good ACoS is one below the break-even ACoS for that product when the goal is profit, or a deliberate number above it when the goal is a launch or ranking. Break-even ACoS is profit per unit before ads divided by the price. Work it out for each product with our break-even ACoS calculator.
A keyword is what you bid on. A search term is what the shopper actually typed. With broad or phrase match, one keyword can trigger many different search terms, which is why the search term report matters.
New-to-brand orders come from shoppers who had not bought from your brand on Amazon in the previous twelve months. Amazon reports it for several ad types, including Sponsored Brands and Sponsored Display, and it shows whether ads are finding new customers.