Blended ROAS (MER)
Total revenue divided by total marketing spend. It's the one ROAS no attribution model can inflate, but it can't tell you which channel or campaign earned the money.
Includes organic, repeat and retention revenue, not just what ads drove.
What is blended ROAS?
Every other ROAS on these pages depends on attribution: a set of rules about which ad gets credit for which order. Blended ROAS skips that question. It takes every rupee of revenue the store made and divides it by every rupee spent on marketing.
That makes it hard to fool. No platform can over-claim it, and no model choice changes it. The trade-off is that it can't point at anything. It tells you whether marketing as a whole is getting more or less efficient, not which lever to pull.
How it's calculated
MER is simple arithmetic. The care goes into deciding what counts as revenue and what counts as spend, then keeping that definition fixed month to month.
| Input | Source | Decide upfront |
|---|---|---|
| Total revenue | Shopify, plus other sales channels you include | Gross or net of cancellations and RTO? Include Amazon and quick commerce? |
| Ad spend | Every ad platform | All paid channels, including smaller ones |
| Other marketing cost | Influencer fees, agency fees, tools | Whether these sit in the denominator |
Worked examples
Example 1: MER as spend scales
An illustrative brand grows monthly spend from โน20 lakh to โน36 lakh between July and October 2026. Revenue grows too, but MER slides each month.
| Month | Total spend | Total revenue | MER | Incremental MER |
|---|---|---|---|---|
| Jul | โน20,00,000 | โน80,00,000 | 4.00 | โ |
| Aug | โน25,00,000 | โน92,50,000 | 3.70 | 2.50 |
| Sep | โน30,00,000 | โน1,02,00,000 | 3.40 | 1.90 |
| Oct | โน36,00,000 | โน1,11,60,000 | 3.10 | 1.60 |
- The headlineMER drops from 4.00 to 3.10. Gentle on its own, and still comfortably profitable for many brands.
- The real storyThe extra โน6 lakh in October bought only โน9.6 lakh of extra revenue, an incremental MER of 1.60. Average MER hides how much worse the last rupee is doing.
- What MER can't sayWhich channel saturated. For that you need channel-level true ROAS and marginal ROAS.
Example 2: Same MER, very different months
Two months with โน20 lakh spend and โน70 lakh revenue each. MER is 3.50 both times.
Using MER to decide
Use MER as the guardrail and channel-level true ROAS as the steering wheel. Set your MER floor from your margins, then read these as starting rules.
Common mistakes
- Using MER to pick channelsIt has no channel detail. Shifting budget on MER alone is guesswork.
- Changing the definitionAdding Amazon revenue one month and not the next breaks the trend.
- Crediting retention to adsStrong repeat or email months inflate MER without paid doing anything new.
- Reading average, not marginalA healthy average can hide a last few lakh of spend that barely returns.
Frequently asked questions
Is MER the same as blended ROAS?
Yes, the two names are used for the same ratio: total revenue over total marketing spend. Some teams include agency and influencer fees in spend; say which you use.
What is a good MER?
It depends on your margins. Work out the MER at which contribution margin covers all marketing, and treat that as your floor. Break-even ROAS shows the method.
Should I use MER instead of attribution?
Use both. MER keeps attribution honest at the top level. Attribution tells you where within the mix to act.
Related metrics
MER and true ROAS in one view
BooleanMaths brings revenue and spend from every channel together, so you see blended ROAS alongside the channel-level true ROAS behind it.
Blended ROAS (MER)
Total revenue divided by total marketing spend. It's the one ROAS no attribution model can inflate, but it can't tell you which channel or campaign earned the money.
Includes organic, repeat and retention revenue, not just what ads drove.
What is blended ROAS?
Every other ROAS on these pages depends on attribution: a set of rules about which ad gets credit for which order. Blended ROAS skips that question. It takes every rupee of revenue the store made and divides it by every rupee spent on marketing.
That makes it hard to fool. No platform can over-claim it, and no model choice changes it. The trade-off is that it can't point at anything. It tells you whether marketing as a whole is getting more or less efficient, not which lever to pull.
How it's calculated
MER is simple arithmetic. The care goes into deciding what counts as revenue and what counts as spend, then keeping that definition fixed month to month.
| Input | Source | Decide upfront |
|---|---|---|
| Total revenue | Shopify, plus other sales channels you include | Gross or net of cancellations and RTO? Include Amazon and quick commerce? |
| Ad spend | Every ad platform | All paid channels, including smaller ones |
| Other marketing cost | Influencer fees, agency fees, tools | Whether these sit in the denominator |
Worked examples
Example 1: MER as spend scales
An illustrative brand grows monthly spend from โน20 lakh to โน36 lakh between July and October 2026. Revenue grows too, but MER slides each month.
| Month | Total spend | Total revenue | MER | Incremental MER |
|---|---|---|---|---|
| Jul | โน20,00,000 | โน80,00,000 | 4.00 | โ |
| Aug | โน25,00,000 | โน92,50,000 | 3.70 | 2.50 |
| Sep | โน30,00,000 | โน1,02,00,000 | 3.40 | 1.90 |
| Oct | โน36,00,000 | โน1,11,60,000 | 3.10 | 1.60 |
- The headlineMER drops from 4.00 to 3.10. Gentle on its own, and still comfortably profitable for many brands.
- The real storyThe extra โน6 lakh in October bought only โน9.6 lakh of extra revenue, an incremental MER of 1.60. Average MER hides how much worse the last rupee is doing.
- What MER can't sayWhich channel saturated. For that you need channel-level true ROAS and marginal ROAS.
Example 2: Same MER, very different months
Two months with โน20 lakh spend and โน70 lakh revenue each. MER is 3.50 both times.
Using MER to decide
Use MER as the guardrail and channel-level true ROAS as the steering wheel. Set your MER floor from your margins, then read these as starting rules.
Common mistakes
- Using MER to pick channelsIt has no channel detail. Shifting budget on MER alone is guesswork.
- Changing the definitionAdding Amazon revenue one month and not the next breaks the trend.
- Crediting retention to adsStrong repeat or email months inflate MER without paid doing anything new.
- Reading average, not marginalA healthy average can hide a last few lakh of spend that barely returns.
Frequently asked questions
Is MER the same as blended ROAS?
Yes, the two names are used for the same ratio: total revenue over total marketing spend. Some teams include agency and influencer fees in spend; say which you use.
What is a good MER?
It depends on your margins. Work out the MER at which contribution margin covers all marketing, and treat that as your floor. Break-even ROAS shows the method.
Should I use MER instead of attribution?
Use both. MER keeps attribution honest at the top level. Attribution tells you where within the mix to act.
Related metrics
MER and true ROAS in one view
BooleanMaths brings revenue and spend from every channel together, so you see blended ROAS alongside the channel-level true ROAS behind it.