MER (marketing efficiency ratio) is total revenue divided by total marketing spend for the same period. Because it needs no attribution model, it is the honest top-line check on whether marketing as a whole is paying off, though it cannot tell you which channel is doing the work.
What is the marketing efficiency ratio?
MER measures how much revenue marketing generates for every dollar spent: total revenue divided by total marketing spend for a period.1Source 1 · HubSpotMarketing efficiency ratio: How to calculate and improve yoursblog.hubspot.com It is sometimes called blended ROAS, though tools disagree on whether the denominator is ad spend only or all marketing cost. Because it ignores attribution entirely, it is immune to platforms double-counting conversions, the weakness of ROAS.
Worked example
| Month | Revenue | Marketing spend | MER | Sum of platform ROAS revenue |
|---|---|---|---|---|
| April | $1,200,000 | $240,000 | 5.0 | $1,050,000 |
| May | $1,260,000 | $300,000 | 4.2 | $1,390,000 |
HubSpot’s guide makes the same split: ROAS shows where spend should be allocated, MER shows whether total marketing spending is generating profitable revenue, and high ROAS alongside declining MER may indicate overspending on upper-funnel channels.1Source 1 · HubSpotMarketing efficiency ratio: How to calculate and improve yoursblog.hubspot.com
Common mistakes
- Comparing MER across businesses with different repeat-purchase rates. A brand with heavy repeat revenue gets a high MER even with weak acquisition.
- Changing the denominator month to month (adding agency fees in some months).
- Reading short windows. Spend often converts weeks later; use rolling 4- or 13-week MER.
- Using MER to cut a single channel. It cannot isolate channels; that needs incrementality tests or media mix modeling.
How to track MER in Kimo
Kimo sums spend across every connected ad account (Google Ads, Meta, TikTok, LinkedIn) and divides by revenue from Shopify or Stripe, with the revenue definition stored once in your data model. The Command center puts MER next to platform ROAS, and the marketing command center template ships both.
Frequently asked questions
Is MER the same as blended ROAS?
What is a good MER?
Sources
1 reference- Marketing efficiency ratio: How to calculate and improve yours (opens in a new tab)HubSpotblog.hubspot.com
MER = total revenue ÷ total marketing spend; MER vs ROAS.
External sources were accessed at the time of writing. Kimo product details, customers and figures in examples are illustrative unless a source is cited.
