Every Amazon seller watches their ACoS. Few track their TACoS. That's a mistake, because TACoS tells you whether your advertising is actually building your business — or just maintaining it.
ACoS (Advertising Cost of Sale)
ACoS = Ad Spend ÷ Ad Revenue × 100
If you spend £100 on ads and generate £500 in ad-attributed revenue, your ACoS is 20%. Simple. It tells you how efficiently your ads convert.
TACoS (Total Advertising Cost of Sale)
TACoS = Ad Spend ÷ Total Revenue × 100
This includes all revenue — organic + ad-attributed. If you spend £100 on ads and your total revenue (organic + paid) is £2,000, your TACoS is 5%.
Why TACoS Matters More
If your ACoS is stable but your TACoS is decreasing, it means your organic sales are growing. Your advertising is building momentum that carries beyond the ads themselves. This is the goal.
If your ACoS is stable but your TACoS is increasing, your organic sales are declining. You're becoming more dependent on ads, which is unsustainable.
Target Metrics
| Metric | Launch Phase | Growth Phase | Mature Product |
|---|---|---|---|
| ACoS | 40–60% | 20–35% | 15–25% |
| TACoS | 15–25% | 8–15% | 5–10% |
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