The new profit discipline for modern e-commerce

MER tells you how much revenue your marketing generates.

MPR tells you how much profitable contribution it creates — and that’s what decides survival.

The end of “efficiency theater”

For years, DTC brands have celebrated MER — the Marketing Efficiency Ratio — as the holy grail of performance. It seemed simple: the higher your MER, the better.

But simplicity became blindness.

MER shows how much revenue your marketing produces, but says nothing about what’s left after product costs, shipping, and transaction fees.

When costs rise or returns increase, MER still looks great while profit disappears.

Efficiency is meaningless if it scales losses.

That’s why every brand needs to replace MER with MPR: the Marketing Profitability Ratio — the metric that measures how much contribution margin (2) your marketing truly creates.

The flaw inside MER

Your MER formula:

MER = Net Revenue ÷ Marketing Spend

If MER = 5, you generate €5 in revenue for every €1 of marketing spend.

That sounds impressive, but it can be deceptive.

MER ignores:

• Rising COGS and logistics costs
• Returns inflating gross revenue
• Transaction fees eroding margin
• Differences between retained and new customers

You can scale MER while your margins collapse — a brand growing fast but earning nothing.

CM2 — the real foundation

To measure marketing’s true economic impact, you need CM2: contribution margin 2.

It isolates the profit pool available before marketing and overhead.

Formula

CM2 = Net Revenue − COGS + COGS Returned − Shipping Cost − Transaction Cost

CM2 shows what’s truly left to fund marketing and operations.

Without it, every “profit” discussion is guesswork.

Introducing MPR, aMPR & New Customer MPR

Reactivated customers are customers who were previously inactive or churned, meaning they haven’t purchased for a long period (e.g., 180 days depending on your product).

Higher is better.

If MPR = 2.7, every euro spent produces €2.70 in contribution margin.

If aMPR = 1.2, your acquisition engine is sustainable — you’re buying profitable growth.

MER vs MPR — the wake-up example

MER = 500 000 ÷ 100 000 = 5.0

MPR = 270 000 ÷ 100 000 = 2.7

MER says you make €5 in revenue per €1 spent.

MPR shows you make €2.70 in contribution margin 2 per €1 spent — the figure that actually funds your company.

Cohort breakdown:

• CM2 from new + reactivated = 80 000 → aMPR = 0.8
• CM2 from new only = 60 000 New Customer MPR = 0.6

MER looks great.

MPR shows the truth.

aMPR reveals that your “growth” is still unprofitable at first purchase.

aMPR — the real growth lever

Total MPR shows how profitably your entire marketing system performs.

aMPR isolates what matters most: whether you’re acquiring new value or just inflating top-line numbers.

• aMPR < 1.2 → unprofitable growth (CM2 does not include operational cost like rent, salaries)
• aMPR ≈ 1.5 → healthy, sustainable growth
• aMPR > 2.0 → compounding profitability

Your rule of thumb:

“Scale acquisition when aMPR ≥ 1.2. Hold or optimize when it drops below 1.2”

That’s how you move from guessing to governing.

From efficiency to profitability — how to transition

1. Build CM2 visibility

Integrate COGS, shipping, transaction fees, and returns.

Compute CM2 per order, product, or cohort.

1. Segment marketing spend.

Tag campaigns by acquisition, reactivation, and retention.

Map spend to CM2 for each group.

2. Define guardrails

• Target MER ≥ 3.0
• Target MPR ≥ 2.0
• Target aMPR ≥ 1.2

3. Educate your team

Show the same campaign under MER and MPR.

Once they see the difference, MER loses its shine.

4. Run both metrics for one quarter

Compare them side-by-side.

When leadership sees that MPR aligns with profit reality, make it the new north star.

The objections

“MER is industry standard.” > So was ROAS — until everyone realized it was fiction. “Finance already tracks profit.” > Finance looks backward. MPR gives a real-time view of profitability.“Attribution is messy.” > It doesn’t need to be perfect — directionally correct is enough.“MPR penalizes growth brands.” > It enforces discipline. Growth only counts when it compounds margin.

The bottom line

MER shows how efficiently you generate revenue.

MPR shows how profitably you do it.

Revenue is vanity.

Efficiency is temporary.

Profitability is truth.

MPR tells you how much profit your marketing really creates.

FAQ Section

What is MPR in marketing?

MPR (Marketing Profitability Ratio) measures how much contribution margin your marketing generates per euro spent. Unlike MER which only tracks revenue, MPR accounts for product costs, shipping, transaction fees, and returns to show true profitability. If your MPR is 2.7, every euro of marketing spend creates €2.70 in actual contribution margin available to fund operations and growth.

What's the difference between MER and MPR?

MER (Marketing Efficiency Ratio) calculates revenue divided by marketing spend, while MPR divides contribution margin 2 (CM2) by marketing spend. MER can look impressive even when you're losing money because it ignores product costs, shipping, and fees. MPR reveals the real economic impact of your marketing by showing profit contribution rather than just top-line revenue.

What is a good MPR ratio?

A healthy MPR is 2.0 or higher, meaning you generate €2 in contribution margin for every €1 spent on marketing. For acquisition-focused metrics, aMPR should be at least 1.2 to ensure sustainable growth after accounting for operational costs. Brands with MPR below 1.5 should optimize campaigns before scaling, as they're not generating sufficient margin to fund long-term operations.

How do you calculate contribution margin 2 (CM2)?

CM2 equals net revenue minus COGS plus COGS returned minus shipping costs minus transaction costs. This formula isolates the profit pool available before marketing spend and overhead expenses. CM2 shows what's truly left after fulfilling orders, making it the foundation for accurate profitability measurement in e-commerce.

When should I scale my marketing based on MPR?

Scale acquisition when your aMPR (acquisition MPR for new and reactivated customers) reaches 1.2 or higher. Below 1.2, focus on optimizing campaigns and improving unit economics before increasing spend. An aMPR of 1.5 or higher indicates healthy, sustainable growth that compounds profitability rather than just inflating revenue numbers.

Can I use both MER and MPR together?

Yes, running both metrics provides complementary insights during transition periods. MER shows top-line efficiency while MPR reveals true profitability. However, MPR should become your primary decision-making metric because it aligns with actual business survival. Use MER as a secondary indicator, but never let high MER convince you to scale unprofitable campaigns.