ROI on Amazon Ads: ACoS, TACoS and how to know if your campaigns are profitable
Amazon Ads has its own metric vocabulary: ACoS instead of ROAS, TACoS instead of overall ROI. But the logic is the same — compare what you spend with what you earn. The difference is that on Amazon advertising also impacts organic ranking, which changes the profitability calculation.
How advertising on Amazon works (and why it's different)
On Meta, TikTok or Pinterest, the user isn't looking to buy when they see the ad. On Amazon, every user already has purchase intent: they're searching for a specific product to buy. Advertising on Amazon doesn't generate demand — it captures demand that already exists.
This has two direct consequences for ROI:
Advantage
Conversion rates are 3-10x higher than on social media advertising. A 0.5% CTR on Meta and a 0.3% CTR on Amazon can result in the same number of final sales because Amazon's conversion is much higher.
Complexity
Amazon ads compete against other sellers of the same product. In competitive niches CPCs can be very high, and ROI depends as much on advertising strategy as on price and reviews of the listing.
ACoS: the profitability metric of Amazon Ads
Amazon doesn't use ROAS as the main metric — it uses ACoS (Advertising Cost of Sale): the percentage of ad spend over the revenue generated by the ads.
ACoS formula
ACoS = Ad spend ÷ Attributed revenue × 100
ACoS is the inverse of ROAS expressed as a percentage:
| ACoS | Equals ROAS | Profitable if margin > |
|---|---|---|
| 10% | 10x | 10% |
| 20% | 5x | 20% |
| 30% | 3.33x | 30% |
| 40% | 2.5x | 40% |
| 50% | 2x | 50% |
Key rule: the break-even ACoS equals your gross margin on Amazon (sale price − product cost − Amazon fees − FBA if applicable). If ACoS is below margin, the campaign is profitable. If above, you're losing money.
TACoS: why this metric matters more than ACoS
ACoS only measures the profitability of sales directly attributed to ads. But advertising on Amazon has a very important secondary effect: it improves the product's organic ranking, generating additional organic sales that don't show up in ACoS.
TACoS (Total Advertising Cost of Sale) measures ad spend over total sales for the period (paid + organic):
TACoS formula
TACoS = Ad spend ÷ Total sales × 100
Example: same spend, same attributed sales, but different TACoS
ACoS barely changes between month 1 and month 6. But TACoS is cut in half because the product has gained organic ranking and generates sales without advertising. This is what makes a seemingly high ACoS at the start a justified strategic investment: you're paying for future organic ranking.
The three types of Amazon Ads campaigns
Sponsored Products
Ads that appear in search results and on competitor product pages. They have the highest purchase intent and usually generate the best ACoS. Ideal to start with: test automatic keywords first to identify the search terms that convert best.
Best for: established products, initial launches
Sponsored Brands
Banner at the top of search results showing the logo and 3-4 products. You need a brand registered in Amazon Brand Registry. ACoS is usually higher than Sponsored Products, but they build brand recognition within Amazon and can capture traffic from generic searches.
Best for: established brands, categories with multiple products
Sponsored Display
Display ads that can appear inside and outside Amazon (on third-party sites). They allow retargeting users who visited your product page without buying. ACoS can be variable, but they're especially useful for recovering users who were close to buying.
Best for: retargeting, complement to Sponsored Products
Real margin on Amazon: more costs than in your own store
ROI on Amazon includes costs that don't exist in your own store. Before calculating whether campaigns are profitable, you need to know your real margin on Amazon:
Cost structure on Amazon (example: €35 product)
With a maximum ACoS of 35.6%, any campaign with an ACoS below that figure generates profit. Campaigns above destroy margin. This number is your guide for setting maximum bids on each keyword.
Amazon Ads vs. your own store: where is it more profitable?
The question many sellers ask: should I invest in Amazon Ads or in Meta/TikTok to drive traffic to my own store?
| Factor | Amazon Ads | Meta/TikTok → your store |
|---|---|---|
| Available margin | Lower (−Amazon fees) | Higher (no fees) |
| Conversion rate | High (5-15%) | Low (1-3%) |
| Buyer trust | High (Amazon guarantees) | Variable (you have to build it) |
| Customer control | None (Amazon retains them) | Total (email, remarketing) |
| Customer LTV | Low (buys on Amazon, not your brand) | High (you can retain and build loyalty) |
| Speed to results | Fast | Slower (learning phase) |
The most robust long-term strategy is to use Amazon for volume and speed in the early stages while building your own brand with direct traffic from social media. Amazon captures existing demand; social media creates new demand and builds customer LTV.
Calculate the ROI of your Amazon campaigns
Use the calculator with your real margin on Amazon (after fees and FBA) to know if your campaigns are profitable.
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