TACoS, or Total Advertising Cost of Sales, is an Amazon advertising metric that expresses ad spend as a percentage of total revenue — both ad-attributed and organic sales combined. Unlike ACoS, which only compares ad spend to ad-attributed sales, TACoS measures whether PPC investment is actually growing the whole business or just recycling revenue the brand would have earned anyway.
Why It Matters for Sellers
TACoS is the single most useful health metric for an Amazon PPC program because it captures the halo effect of paid traffic on organic ranking. A stable or declining TACoS while sales grow means ad spend is compounding into organic momentum — every dollar of PPC is lifting keyword rank, review velocity, and BSR, and organic sales are outpacing paid ones. A rising TACoS while sales stagnate is a warning sign: the brand is becoming dependent on ads to hold its position, and organic health is eroding underneath.
How TACoS Is Calculated
TACoS = (Total Ad Spend / Total Revenue) x 100
Where Total Revenue = Ad-Attributed Sales + Organic Sales.
Worked example:
- Ad spend: $2,000
- Ad-attributed sales: $8,000
- Organic sales: $12,000
- Total revenue: $20,000
- TACoS = ($2,000 / $20,000) x 100 = 10%
For comparison, ACoS on the same data = $2,000 / $8,000 = 25%. The two metrics tell very different stories: ACoS looks at ad campaign efficiency in isolation; TACoS looks at the business.
TACoS vs ACoS
| Metric | Formula | What It Measures |
|---|---|---|
| ACoS | Ad Spend / Ad Sales | Campaign-level efficiency |
| TACoS | Ad Spend / Total Sales | Business-level dependency on ads |
| ROAS | Ad Sales / Ad Spend | Inverse of ACoS |
A launch phase typically runs high TACoS (20-40%) intentionally to buy ranking. A mature product should trend toward 5-15% TACoS as organic sales dominate.
Common Mistakes
- Optimizing only for ACoS and starving new launches of the visibility they need to gain organic rank.
- Ignoring rising TACoS on mature SKUs — a signal that competitors are eroding your organic share.
- Comparing TACoS across categories without context; a $200 supplement and a $12 phone case have very different sustainable ranges.
- Treating TACoS as a fixed target instead of a trend to monitor month-over-month.
How SellerSonar Helps
- Ranking Monitoring tracks BSR and organic keyword rank so you can see whether ad spend is actually lifting organic position — the outcome TACoS is designed to measure.
- Keyword Monitoring shows movement on the specific search terms your PPC campaigns target, so you know when organic rank is strong enough to reduce bids.
Start your free SellerSonar trial today.
Related Terms
- ACoS — the campaign-level cousin that TACoS puts in context
- Sponsored Products — the ad type driving most Amazon ad spend
- Search Query Performance (SQP) — the Brand Registry data source for measuring organic vs paid share