The Definitions, Clearly
ACOS (Advertising Cost of Sales) = Ad Spend ÷ Ad Revenue × 100
This only measures the efficiency of your paid traffic. A 30% ACOS means you spent ₹30 in ads for every ₹100 in revenue that was attributed to those ads.
TACOS (Total Advertising Cost of Sales) = Ad Spend ÷ Total Revenue (organic + ad) × 100
This measures your ad spend against all revenue, not just ad-attributed revenue. A 30% ACOS account with ₹2L in total monthly revenue (₹1L organic, ₹1L ad-attributed) has a TACOS of 15%, not 30%.
Why ACOS Alone Is Misleading
ACOS ignores organic revenue entirely. If your PPC investment is successfully building organic rank — which is the goal of any properly structured Amazon PPC strategy — your ACOS will look worse even as your business becomes more profitable.
Here's a concrete example: You're spending ₹50,000/month on PPC, generating ₹1,00,000 in ad-attributed revenue (50% ACOS) and ₹2,00,000 in organic revenue. Total revenue: ₹3,00,000. TACOS: 16.7%. Your business is very healthy. But if you only look at ACOS, you might cut spend because 50% looks terrible.
"We've seen sellers who reduced ad spend to 'improve ACOS' and watched their total revenue fall 40% as organic rank collapsed. They optimized the wrong number."
When Each Metric Matters
Use ACOS for:
- Evaluating individual keyword efficiency
- Comparing campaign types (SP vs SB vs SD)
- Setting bid targets at keyword level
- Short-term campaign optimization decisions
Use TACOS for:
- Evaluating overall account health
- Making budget decisions (increase or decrease total spend)
- Measuring launch success
- Reporting to stakeholders or investors on ad efficiency
- Trend analysis over months — is PPC becoming more or less efficient over time?
What's a Good TACOS?
This varies significantly by category, account maturity, and growth stage. As a rough guide:
- Mature account, stable growth: 8–15% TACOS is healthy for most categories
- Active growth phase: 15–25% TACOS may be acceptable if organic rank is improving
- Launch phase: 30–50%+ TACOS is normal in the first 30–60 days
- Warning sign: TACOS above 25% on an account older than 6 months with flat organic revenue suggests PPC is propping up the account rather than building it
The Trend Is More Important Than the Number
- A falling TACOS over 6 months means your organic share is growing — PPC is working as designed
- A flat TACOS despite increasing spend means organic revenue isn't growing — diagnose before adding budget
- A rising TACOS means organic is declining — check for rank drops, listing suppression, or increased competition
- Compare TACOS this month to same period last year for seasonality-adjusted insight
How to Calculate Your TACOS
You need two numbers from Seller Central: total ad spend (from the Advertising dashboard) and total sales (from Business Reports → By ASIN). Divide spend by total sales and multiply by 100. If you're using Helium 10 or DataRova, both calculate TACOS automatically and show you the trend over time.
Track TACOS monthly. Plot it. A chart of TACOS over 12 months tells you more about the health of your Amazon business than any other single number.
Start With a Free Audit
Every Bidvista engagement starts with a no-obligation 15-point audit.