Every ecommerce team has a version of the same argument running quietly in the background. How much goes to Meta, how much goes to Google, and who gets the credit when a sale comes through.
Usually it gets settled by whoever argues hardest, or who believes most in a particular channel, or an attribution model nobody has questioned in two years. And the numbers everyone is arguing with come straight off the ad platforms.
That last part is the whole problem. Add up what Meta, Google and your email tool each claim they drove, and you will land north of 200% of the revenue that actually hit your bank account. Everyone is taking credit for the same sale, so the debate gets run on numbers that don’t add up.
In this playbook, we cover three things ecommerce operators can take into their business:
- The question that matters isn’t your channel ratio, it’s what each specific campaign is trying to do
- Every ad platform is built to over-claim, so you need one honest top-line number before you judge any single channel
- Independent measurement earns its keep, but only when it’s right-sized to your business
What Is Mixed Media Modelling?
Mixed media modelling (MMM) is a measurement approach that uses independent data to estimate how each marketing channel contributes to revenue, including channels you can’t track with a click. It pulls in above-the-line spend like TV, radio and outdoor alongside digital performance channels, then models what happens to revenue when you increase or decrease each one. The key word is independent. The numbers don’t come from the platforms that want your budget, which is exactly why operators use it to settle channel arguments that opinions can’t.
The Data Girl Who Wanted to Give It All to Google
Paula Mitchell has spent five years as Digital GM at Freedom, running fifty stores and seventy thousand products with a team of twelve. She has won just about every ecommerce award going, and she describes herself as the data girl who would happily hand all the budget to Google.
What changed her mind wasn’t an opinion. Freedom implemented mixed media modelling across the business, refreshing the data every month and feeding in every channel, above the line and digital. The model showed her something she didn’t expect.
“There’s been chatter forever about TV being dead. The data, and it’s independent data, it definitely tells us TV is not dead. And I’m the digital girl, right? Give me all the money for Google. It’s been a learning. They all have a role to play.”
That’s the thing about independent data. It earns its keep precisely when it contradicts you.
Match the Channel to the Job, Not a Fixed Ratio
Stop running every campaign through the same Meta and Google split. The question that matters isn’t your channel ratio, it’s what this specific campaign is trying to do.
An upper-funnel job, getting someone to fall for an idea, belongs where people browse for inspiration. For Freedom coming into Christmas, that’s table settings and entertaining on Pinterest, Instagram and TikTok. A bottom-funnel job, a flash sale closing in twelve hours, belongs where the intent already exists. That’s Google. Where teams get caught is holding both to the same last-click ROAS target, which switches off the awareness work that was never meant to convert on the first click.
Muscle Nation‘s Emilio Murphy is about as data-led as paid operators get, and he makes the same point about not judging every channel by last click.
“Not everything has to be profitable last click. TikTok traditionally isn’t a platform that converts as strongly as Meta, because inherently it’s designed to keep you on the platform. So we use it not only as a conversion platform, but as a way to measure impact from other platforms.”
So before the next campaign, write down the one job it has to do, then pick the channel that does that job. Not the channel you’re most comfortable in.
Stop Trusting the Platforms’ Own Numbers
Every ad platform is built to over-claim, because the more credit it takes, the more budget you hand it. Any dashboard you own and have built yourself will be more trustworthy for your situation than a platform’s own reporting.
Here’s the check you can run today. Take your actual revenue from your store, then add up what Google, Meta and Klaviyo each say they drove. You’ll sail past 100%, because they’re all counting the same customer. Iain Calvert from Boom has run that exact test more times than anyone.
“Add it together and you’re probably going to be about 250% of your sales. There’s a really good metric called marketing efficiency ratio, MER, the percentage of your revenue you spend on advertising. That’s the way I manage every account, from a 500 grand site to a 25 million dollar site.”
Pick one honest top-line number like MER and judge the whole engine on it before you judge any single channel.
Buy Independent Measurement, Sized to Your Business
Once you accept the platforms can’t referee their own game, you need a source of truth that sits outside them. For Freedom, mixed media modelling ended a long-running internal argument with data instead of opinions.
But right-size it. Most operators don’t need a full modelling platform, and reaching for one before you’re ready is its own kind of waste. Adam Sharon-Zipser draws the line at a spend threshold, and his advice for the ninety percent of retailers below it is the practical part. Brands under roughly 250,000 dollars a month in spend are better served by incrementality testing, changing one thing and measuring the impact on your north stars, then pacing an aggregate number like MER over time.
Decide which tier you’re in, then build the smallest measurement system that gives you a number the platforms didn’t.
The Takeaway
The channel question and the measurement question are the same question. You can’t decide where the money goes until you have a number that isn’t being marked by the same platform that wants the money. Match the channel to the job, judge the whole engine on one honest top-line number, and bring in independent data when the stakes are big enough.
Frequently Asked Questions
What is mixed media modelling in ecommerce? Mixed media modelling (MMM) is a statistical approach that uses independent data to estimate how each marketing channel contributes to revenue, including untrackable channels like TV and outdoor. It models what happens to revenue when you increase or decrease spend on each channel, giving operators a view that doesn’t come from the ad platforms themselves.
What is marketing efficiency ratio (MER) and how do you use it? MER is the percentage of your total revenue that you spend on advertising across all channels. A lower MER means your ads are more efficient and you can likely afford to spend more, while a higher MER signals your advertising is becoming less efficient. It works as a single honest top-line number because it’s calculated from your actual revenue, not platform-reported sales.
Why do my ad platforms report more sales than I actually made? Each platform claims credit for any sale it touched, so when a customer sees a Google ad, a Meta ad and an email before buying, all three count the same purchase. Add up what Google, Meta and Klaviyo each report and you’ll often reach around 250% of your real revenue, because the platforms are all counting the same customers.
How do you decide your Meta versus Google budget split? Start from the objective of each campaign rather than a fixed ratio. Upper-funnel, inspiration-led campaigns suit browsing platforms like Pinterest, Instagram and TikTok, while bottom-funnel, high-intent campaigns like flash sales suit Google. The right split changes campaign by campaign depending on what you’re trying to achieve.
Based on Episode #624 of the Add To Cart podcast with with Paula Mitchell, Digital GM, Freedom. Join the Add To Cart community for free.
In this Playbook:
- The right channel mix comes from each campaign’s job, not a fixed Meta and Google ratio.
- The platforms can’t referee their own game, so judge the whole engine on one honest number like MER.
- Independent measurement is worth it, but only when it’s sized to your business.
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