Marketing Efficiency Ratio (MER): the metric that survives dark social

TL;DR

The Marketing Efficiency Ratio equals total revenue divided by total marketing spend. It ignores attribution entirely and answers the one question every CFO actually asks: for every euro of marketing, how many euros of revenue.

• MER benchmarks for B2B SaaS: Series A 2-4x, Series B 3-6x, Enterprise 4-10x.
• MER survives dark social because it does not depend on tracking. Total revenue is knowable; total marketing spend is knowable; the ratio is honest.
• Use MER for top-down efficiency; use multi-touch attribution for channel optimisation; use self-reported attribution for buyer-behaviour insight.
• Below 2x at any stage suggests marketing inefficiency; above 10x suggests marketing underinvestment.

Introduction

Chris Walker’s argument, delivered on LinkedIn hundreds of times over five years, resolves to a single practical question: if attribution is broken, what should the CFO and the CMO agree to measure?

The answer that has quietly become the consensus in mid-market B2B SaaS is the Marketing Efficiency Ratio (MER). Total revenue divided by total marketing spend over a defined period. Blind to attribution. Blind to channel. Blind to the dark-social conversation that no tracker sees. Honest about the aggregate efficiency of the marketing function.

This article is the field guide for B2B CMO, CFO or head of finance who wants to add MER to their measurement stack in 2026. It covers the formula, the benchmarks, the pitfalls, and the reconciliation with the other measurement tools already in use.

The formula and what it includes

MER = Total revenue / Total marketing spend, over a defined period.

Total revenue is straightforward at the company level: recognised revenue over the period, or new-business ARR added, or a specific segment of both. Which specific revenue definition you use matters and needs to be documented explicitly.

Total marketing spend is where teams disagree. The honest, defensible definition includes everything the marketing function consumes:

• Paid media (Google Ads, LinkedIn Ads, Meta Ads, ABM display, sponsored content)
• Marketing team compensation (salaries, bonuses, contractors)
• Marketing tools (marketing automation, attribution tools, CMS, design tools, video production)
• Events (sponsorships, hosted events, trade shows)
• Content production (agency, freelancer, video, design)
• Brand and PR (agency, sponsorships, brand campaigns)
• Community and dark-social investment (podcast production, community management)

Some teams argue for excluding brand spend from MER on the theory that brand has long-tail effects that a single period cannot capture. This is defensible but adds complexity. The simpler, more auditable approach is to include everything and use a trailing 12-month window to smooth out the timing lag.

The formula is deliberately blunt. Its virtue is that both inputs are knowable at the CFO level and the ratio is comparable across periods and across companies.

Why MER survived dark social

Three properties make MER robust to the measurement environment of 2026.

It does not depend on tracking. MER does not care whether the buyer came from Google, LinkedIn, a peer conversation, a ChatGPT recommendation or a podcast clip. Total revenue happened; total spend happened; the ratio is calculable.

It does not depend on attribution model choice. Multi-touch, U-shaped, W-shaped, data-driven attribution are all methodological choices with defensible cases for and against. MER makes no such choice. The CFO cannot argue with a ratio that has no model behind it.

It aggregates the invisible. Dark social, AI-engine discovery, peer referral, community-driven awareness all show up in MER as revenue that the marketing function contributed to producing, even when the tracker cannot see the specific touchpoint. As Chris Walker argues:

“Sales metrics like MQLs and Stage 1 pipeline are grossly misaligned to the actual goal of demand generation.”

MER is misaligned with nothing except attribution. It measures what the CFO cares about: aggregate efficiency of marketing investment.

The benchmark ranges

Benchmarks vary by stage, motion and category. The ranges below are what we observe in the Stretch Innovation portfolio of B2B SaaS scale-ups, cross-referenced against publicly-available data from ChartMogul, Bessemer Cloud 100 and Kyle Poyar’s Growth Unhinged benchmarks.

Two boundary interpretations matter.

Below the healthy range. The marketing function is inefficient (spending too much for the revenue produced) or the spend definition is wrong (including costs that belong elsewhere) or the revenue definition is wrong (excluding legitimate marketing-driven revenue). Diagnose in that order.

Above the healthy range. The marketing function is under-invested. Growth is being left on the table because the marketing team is under-resourced or the spend budget is too small for the addressable market. Common failure mode: bootstrapped companies at MER 15x that could have doubled ARR growth with a doubled marketing budget.

MER versus ROAS versus attribution

The three metrics answer different questions and belong at different altitudes.

ROAS (Return on Ad Spend). Channel-level. Revenue per euro of paid-media spend on a specific channel, attributed by a tracking model. Right for weekly campaign optimisation. Wrong for board reporting. Blind to non-paid marketing investment.

Multi-touch attribution. Program-level. Revenue attributed to touchpoints across the funnel. Right for optimisation across channels and program design. Wrong for measuring the aggregate efficiency of the marketing function. Broken by dark social.

MER. Function-level. Revenue over total marketing spend. Right for CFO reporting, board reporting, and quarterly strategic decisions. Wrong for channel optimisation. Blind to which specific investments drove the outcome.

The mature 2026 measurement stack runs all three. ROAS in the marketing team’s daily tool. Multi-touch attribution in the RevOps dashboard. MER in the CFO’s monthly financial review. Each is used for what it can defensibly measure.

The reconciliation between MER and revenue attribution

Some CMOs worry that MER and revenue attribution will disagree in a way that undermines their credibility. The concern is understandable but wrong. The two measure different things at different altitudes and their disagreement is informative rather than problematic.

If MER shows healthy efficiency (say 4x at Series B) and revenue attribution shows 22% of closed-won credited to marketing, both can be true. The marketing function is efficient at its overall contribution (MER); the identifiable and attributable marketing-driven revenue is a portion of the total. The remaining revenue was influenced by marketing (brand, community, dark social) in ways that revenue attribution cannot fully credit but that MER captures aggregately.

The productive quarterly conversation is: does the pattern of MER improvement match the pattern of revenue attribution improvement? If MER is trending up and revenue attribution is flat, marketing is likely contributing to sales-attributed revenue through brand and awareness effects. If MER is flat and revenue attribution is up, marketing is capturing more of what was already there rather than creating new demand.

Adam Robinson’s frame applies:

“Most marketers would say I am an idiot, but I do not believe in attribution. It forces you to focus on the wrong things.”

MER is the metric you focus on when attribution has focused you on the wrong things. Not a replacement; a complement that keeps the strategic conversation grounded in aggregate efficiency.

Common calculation pitfalls

Three specific mistakes appear often in mid-market MER implementations.

Pitfall one: excluding marketing team compensation. MER minus salaries flatters the ratio by 30 to 60 percent. Fine as an internal metric with clear labelling. Wrong for CFO reporting.

Pitfall two: using monthly windows. B2B SaaS sales cycles of 3 to 18 months mean monthly MER is noisy. Trailing 12-month or rolling 4-quarter windows smooth out the noise and are defensible.

Pitfall three: using GAAP revenue for a growth-mode business. For a scale-up whose revenue is growing 40+ percent per year, GAAP revenue lags marketing investment by 6 to 12 months. Some teams use New ARR added in the period as the numerator instead, which aligns timing better but produces a lower absolute number. Document the choice.

New-business MER versus expansion MER

For B2B SaaS teams with meaningful expansion revenue (over 15% of new ARR from existing customers), splitting MER into two ratios adds clarity.

New-business MER = New ARR from new customers / marketing spend attributed to acquisition. Expansion MER = Expansion ARR from existing customers / marketing spend attributed to customer marketing.

The split matters because the two motions have very different economics. New-business MER at 3x is healthy; expansion MER at 8x is healthy. Aggregating hides both signals.

Most B2B SaaS teams under €10M ARR do not need the split (expansion revenue is small enough that aggregate MER is directionally correct). Above €20M ARR the split becomes valuable and above €50M ARR essential.

What CFOs should ask

For a CFO evaluating whether their marketing function is efficient, five questions surface the MER conversation.

One: what is our trailing 12-month MER? If nobody knows, MER is not being tracked; that is the first workstream.

Two: how does our MER compare to public benchmarks for our stage? ChartMogul, Bessemer Cloud 100 and Growth Unhinged publish credible ranges.

Three: what does our MER trend look like over the last 8 quarters? Direction matters more than absolute level. A MER improving from 2.5 to 3.5 over 8 quarters is a healthier signal than a stable MER of 4.

Four: what is included and excluded from our marketing spend definition? Verify that salaries, tools, events and brand are all in. Any exclusion needs a defensible reason.

Five: how does our MER reconcile with our revenue attribution? The gap is informative. A MER of 5 with revenue attribution showing 15% marketing contribution suggests brand and dark-social effects that attribution misses. That is normal and does not undermine either metric.

Frequently asked questions

Is MER really that simple? Yes. The formula is deliberately blunt. The interpretation and the reconciliation with other metrics are where the sophistication sits.

Does MER work for enterprise B2B with 18-month sales cycles? Yes, with trailing 12-month or 4-quarter windows. Do not calculate MER on a single-month basis for enterprise motions.

Should I benchmark my MER against my competitors? Only against public data. Private-company MER benchmarks are unreliable because inclusion rules vary. ChartMogul, Bessemer and Growth Unhinged publish defensible ranges.

Can Falora improve my MER? Yes indirectly. Falora reduces marketing operating cost (automating the work of 1 to 2 marketing FTEs) while increasing qualified meeting volume, which improves both the numerator and the denominator of the ratio.

Does MER apply to product-led growth motions? Yes, with modification. In PLG the marketing function drives free-tier signups and activation, which convert to paid revenue on their own timeline. MER for PLG should use trailing 12-month windows and consider self-serve revenue separately from sales-assisted revenue.

Conclusion

The Marketing Efficiency Ratio is the metric that aged best over the last five years of B2B measurement disruption. It sidesteps the attribution debate. It sidesteps the tracking-versus-privacy trade-offs. It answers the question the CFO actually cares about with a formula both sides can audit.

The mature B2B SaaS measurement stack in 2026 does not choose between MER and attribution. It runs both. MER for top-down efficiency and board-level conversations. Multi-touch and self-reported attribution for tactical optimisation and buyer-behaviour insight. The reconciliation between them is a productive monthly conversation rather than an unresolvable argument.

If you want help implementing MER, revenue attribution and self-reported attribution as a coherent stack, book a 45-minute measurement review with Falora.

Sources

• Chris Walker on LinkedIn
• Kyle Poyar, Growth Unhinged benchmarks
• Bessemer Venture Partners, Cloud 100 2025
• ChartMogul, SaaS Growth Report 2025
• Adam Robinson, RB2B
• Toni Hohlbein, Revenue Formula
• Dreamdata, B2B attribution and MER guidance
• HockeyStack, MER methodology guide

Related reading on Falora

• Revenue attribution vs marketing attribution
• Self-reported attribution: the only B2B attribution that survives
• Supermetrics alternative: the 8 options that actually work
• Looker Studio alternative: the 8 BI tools B2B teams should evaluate
• The outbound agency cost autopsy

About the author

Stijn Van Daele is co-founder of Falora and a partner at Stretch Innovation. He has implemented MER as a board-level metric for 18+ B2B SaaS scale-ups and writes about GTM engineering, autonomous revenue and measurement on LinkedIn.