The short version
Marketing efficiency ratio (MER) is revenue divided by total marketing spend. It doesn't care which channel gets the credit, so it ends the monthly argument over who drove the deal.
For B2B, count new-customer revenue only and read it over a rolling quarter. On a six-month sales cycle, a single month of MER is noise.
Your first-year break-even MER is 1 ÷ gross margin. Below that line, marketing doesn't pay for itself within twelve months.
Pair it with pipeline MER, which moves two quarters before revenue does, and keep ROAS for tuning inside each channel.
Every month, the same meeting. Google Ads says it drove eleven deals. LinkedIn says nine. The agency's report credits both, and sales says most of them came from referrals anyway. Add up what each platform claims and marketing produced more revenue than the business actually booked.
Marketing efficiency ratio is how you stop having that meeting. It's one number, it takes five minutes to calculate, and nobody can argue about whose dashboard it came from.
What is marketing efficiency ratio (MER)?
MER = Revenue ÷ Total marketing spend
If you spent $180,000 on marketing last quarter and brought in $420,000 of revenue, your MER is 2.33. Every marketing dollar came back as $2.33 of revenue.
You'll also see it called blended ROAS: one number for the whole system, instead of a separate claim from each channel. "Total marketing spend" means everything: media, agency fees, tools and the salaries of anyone working on marketing. That's the same cost base as marketing ROI, so the two numbers stay comparable.
MER vs ROAS vs ROI
These three answer different questions. Founders get into trouble when one is used to answer another's question.
ROAS | MER | ROI | |
|---|---|---|---|
Formula | Revenue a platform credits to its own ads ÷ ad spend on that platform | Revenue ÷ total marketing spend | (Gross profit − total marketing cost) ÷ total marketing cost |
Question it answers | Which campaigns and audiences are pulling their weight? | Is marketing as a whole bringing in revenue at a rate we can afford? | Is marketing worth the money once margin is counted? |
How often to read it | Daily or weekly | Monthly, on a rolling quarter | Quarterly |
Best used for | Tuning inside a channel | A whole-system health check | Budget decisions and the board |
ROAS is the number you tune campaigns with, and ROI is the number you make budget calls with, as we cover in ROAS vs ROI. MER sits between them: a check on the whole system you can read every month without a data team.
// The Rule
Tune with ROAS. Check health with MER. Decide with ROI.
Why MER sidesteps the attribution argument
Every ad platform marks its own homework. Google Ads credits a sale to its click, LinkedIn credits the same sale to its ad impression, and Meta credits it to its retargeting ad. Add up the revenue each platform reports and the total is almost always more than what landed in the bank.
Long B2B sales cycles make it worse. By default, Google Ads only counts a conversion if it happens within 30 days of the ad click, and the longest it will look back for Search campaigns is 90 days (Google Ads Help). A deal that takes six months to close has dropped out of view long before it signs. So the platforms claim deals they didn't drive and miss deals they did.
MER skips all of this. It asks one question: across everything we spent, how much revenue came back? There's no model to pick and no debate over who touched the deal first. That's why the most common attribution mistakes can't distort it: it never relied on attribution in the first place.
How to adapt MER for B2B
MER comes from ecommerce, where someone clicks an ad and buys the same afternoon. A B2B firm needs three adjustments.
1. Count new-customer revenue, not total revenue
Renewals, expansion and referral deals push MER up without marketing doing anything. Count first-year contract value from new customers only. Total-revenue MER answers a different question (how efficient is the whole business?) and belongs on a different chart.
2. Read it over a rolling quarter, lagged to your sales cycle
If your average sales cycle is six months, the revenue closing today was paid for two quarters ago. There are two ways to handle that:
Rolling MER: trailing three months of new-customer revenue ÷ trailing three months of spend. It smooths out lumpy months.
Lagged MER: this quarter's new-customer revenue ÷ the spend from one sales cycle earlier. It's closer to cause and effect, but it only reads cleanly if spend has been fairly steady.
3. Add pipeline MER as the early read
Revenue tells you about marketing decisions made six months ago. Pipeline tells you about this quarter.
Pipeline MER = (Qualified pipeline created × Win rate) ÷ Marketing spend
It's a forecast, not a result, but it moves as soon as your marketing changes, and that's the signal you need between quarters. Use your historical win rate on qualified deals, not the rate you hope for. If you're not sure how much pipeline you need in the first place, start with the coverage math.
What a healthy MER looks like
Most published MER benchmarks come from ecommerce brands, and they don't carry over to a B2B services or SaaS firm. Work out your own line from your margin instead.
First-year break-even MER = 1 ÷ Gross margin
At a 60% gross margin, that's 1.67 on first-year new-customer revenue. At that level, the first year of gross profit from the customers you won just covers what you spent to win them. Put another way, your CAC payback period is twelve months.
You can set the line from whatever payback period you're prepared to accept:
Target MER = 12 ÷ (Gross margin × Payback months)
Gross margin | 6-month payback | 12-month payback | 18-month payback |
|---|---|---|---|
40% | 5.00 | 2.50 | 1.67 |
60% | 3.33 | 1.67 | 1.11 |
80% | 2.50 | 1.25 | 0.83 |
A payback longer than twelve months only works if customers reliably stay into year two. A high-margin SaaS firm that keeps customers for years can live on the 18-month line. A services firm with 40% margins and annual contracts can't. For the payback question in full, see what a healthy B2B CAC looks like.
A worked example
A B2B services firm with $9M in revenue, a 60% gross margin, a six-month sales cycle and a 25% win rate on qualified pipeline. The figures are illustrative.
Q3 marketing spend: $180,000
Media across Google, LinkedIn and Meta: $90,000
Agency fees: $45,000
Tools: $9,000
One in-house marketer: $36,000
What the platforms reported: Google Ads claimed $310,000 of revenue, LinkedIn $190,000 and Meta $60,000. That's $560,000 in total.
What actually closed: $420,000 of first-year contract value from new customers.
The platforms over-claimed by $140,000. Several deals were counted by two or three platforms at once. Meanwhile, three larger deals that started with search clicks back in Q1 weren't counted by anyone, because they signed months after Google stopped looking.
Measure | Calculation | Result |
|---|---|---|
Rolling MER | $420,000 ÷ $180,000 | 2.33, above the 1.67 break-even line |
Lagged MER | $420,000 ÷ $150,000 (Q1 spend) | 2.80, Q1's work was stronger than the rolling number shows |
Pipeline MER | ($1.4M qualified pipeline × 25%) ÷ $180,000 | 1.94, still above the line but falling |
Pipeline MER is the number to act on. Revenue looks healthy because of work done in Q1. Pipeline MER says the Q3 program is weaker, and that will reach revenue around Q1 next year. MER flagged it two quarters early, and nobody had to argue about attribution to see it.
When MER misleads
MER is a blunt instrument, and it fails in five predictable ways.
It can't tell you which channel to cut. A healthy MER can hide a channel that's burning money. Judge each channel against its own target (our guide to what a good ROAS looks like for B2B sets one by margin), and run a holdout test when you need to know what a channel really adds.
It dips when you invest. Raise spend and MER falls for a full sales cycle before revenue catches up. That isn't failure. Check pipeline MER before you pull back.
One large deal can swing it. With 10 to 20 new customers a quarter, a single enterprise contract can double MER. Read the rolling version and keep the deal count beside it.
Price changes move it. Raise prices 15% and MER can rise by up to 15% with no change in marketing at all. Mark pricing changes on the chart.
Referral and founder deals inflate it. If half your new revenue still comes from your network, MER credits marketing with work it didn't do. Ask every new customer how they found you (self-reported attribution) and leave the referral deals out of the top line.
How to track MER each month
Add one row to the dashboard you already review, with five numbers and one line to stay above:
Total marketing spend, trailing three months
New-customer revenue, trailing three months
Rolling MER
Pipeline MER
Your break-even line, from the table above
If rolling MER and pipeline MER both sit above the line, marketing is working, whatever any single platform claims. If pipeline MER falls below it for two months running, act before the revenue drop arrives. For the profit view your board will want, take the same inputs into how to calculate marketing ROI.
Is your MER telling a different story from your agency's dashboard? In a 30-minute Growth Diagnostic we'll work out your break-even line, rolling MER and pipeline MER from your own numbers.
Book a 30-min Growth Diagnostic
Frequently asked questions
What is a marketing efficiency ratio?
It is a single figure showing how much revenue a business brings in for each dollar of total marketing spend, with all channels combined. Many teams call it blended ROAS.
How is MER calculated?
A B2B company divides new-customer revenue by total marketing spend for the same period, where spend includes media, agency fees, tools and marketing salaries. A rolling three-month window gives the most stable reading.
What is the difference between MER and ROAS?
ROAS measures one platform's ads using the revenue that platform credits to itself. MER compares the whole marketing budget with the revenue that actually arrived, so platforms claiming the same deal can't inflate it.
What is a good MER for a B2B company?
It depends on gross margin. The floor for a twelve-month payback is 1 divided by gross margin, so a firm with 50% margins needs an MER of at least 2.0 on first-year new-customer revenue.
Can MER replace marketing attribution?
Not entirely. MER shows whether marketing works as a whole but not which channel is responsible. Most B2B firms get further by pairing MER with asking customers how they found the business than by buying more complex attribution software.