What is blended ROAS?
How is blended ROAS calculated?
Take all revenue for a period. Divide it by media spend across every platform for the same period. No platform decides who gets credit, so there is less to argue about.
Blended ROAS or MER?
Sources disagree. Shopify's blog says MER is "also called blended ROAS" and counts ads, influencer fees, creative production, tools and agency costs in the spend1. Admetrics, another vendor, calls the ratio MER but divides by total paid media spend2. In the vendor sources we checked, the names overlap and the cost line moves.
Our view, as a convention and not an industry standard: the denominator is the difference, so the names should differ.
- Blended ROAS: total revenue ÷ media spend across all platforms.
- MER: total revenue ÷ total marketing cost, including fees, production and tools.
Whenever you see either one, ask what is in the cost line.
What does blended ROAS tell you?
It shows whether revenue is keeping pace with paid media spend. It does not need attribution, so it does not depend on which platform is counting.
It cannot tell you which channel is doing the work. It also counts all revenue, including sales that would have happened without ads, and it is revenue, not profit. For the margin side, see break-even ROAS. For the cause side, see iROAS. The wider comparison is in ROAS vs MER vs POAS.
For ZFD: We use blended ROAS as a health check for the whole account, never to pick winners between channels.
Worked example
Buzzword alert
"Our blended ROAS is healthy."
Usually means: a media-only ratio, with fees, production and tools left out.
Ask: is this on media spend only, and what does it become once fees and production are added?
"Blended ROAS proves the ads work."
Usually means: revenue and spend moved in the same direction. That is correlation.
Ask: what would blended ROAS have been if the ads had been switched off in a test?
FAQ
Is blended ROAS the same as MER?
In some sources, yes, Shopify's blog among them. In our convention, no: blended ROAS uses media spend only and MER uses all marketing cost.
Is a high blended ROAS good?
Not by itself. It is revenue, not profit, and it includes sales that ads did not cause. Compare it with a break-even figure built on margin.
Can blended ROAS compare channels?
No. It has no channel split by design. Channel questions need channel-level methods, such as a test.
Sources
Let’s find what’s actually working.
Next step. See what your numbers look like on explicit assumptions. Use the Is your ROAS real? calculator.