# MMM Without the Math: Why Your Attribution is Lying to You
Let’s be honest: most Brisbane business owners are flying blind, even if they have a screen full of colourful charts.
I’ve sat in boardrooms from Eagle Farm to Milton, and the story is always the same. The marketing manager points to a Google Ads report showing a 4x Return on Ad Spend (ROAS). Then the social media agency sends a report claiming they drove 300 conversions. But when the business owner looks at the actual bank account or their Xero reports, the revenue hasn't budged by nearly that much.
Why? Because digital attribution is fundamentally broken.
If you are relying on "Last Click" or even the "Data-Driven Attribution" inside Google Analytics, you aren't seeing reality; you’re seeing a filtered, biased version of events designed to make ad platforms look good. This is where Marketing Mix Modeling (MMM) comes in.
Historically, MMM was a tool for the Coles and Westpacs of the world—enterprises with $50 million budgets and a team of data scientists. But in 2026, the game has changed. You don't need a PhD to use these principles to stop wasting money.
The Death of the 'Click' and the Rise of Reality
For years, we’ve been addicted to the click. If someone clicked an ad and bought a sourdough loaf, the ad got the credit. But what if that customer saw your billboard on the Story Bridge, heard your spot on Triple M, and then searched for your brand name? Google Ads takes 100% of the credit for a sale that was actually 90% driven by offline awareness.
This is why GA4 is lying to you. The default setups are designed to track paths, not influence.
MMM ignores the individual user path (which is being destroyed by privacy laws anyway) and looks at the big picture: "When I spend $X here, does the total revenue $Y go up?"
Why traditional attribution is failing Australian SMEs
1. The Privacy Wall: iOS 14.5 was just the beginning. With the death of third-party cookies, tracking a user from a Facebook scroll to a website purchase is now a guessing game. 2. The Multi-Device Mess: A tradie in Chermside might see your ad on his iPad at breakfast, check your prices on his iPhone at lunch, and finally book from his laptop at night. Attribution usually sees this as three different people, or only credits the last device. 3. Offline Blindness: If you run a local event or sponsor a local footy club, digital tracking won't show you the impact. MMM will.Quick Win #1: The "Correlation Sprint" (No Software Required)
You don't need expensive software like Robyn or LightweightMMM to start. You can do a "Poor Man’s MMM" in an afternoon using Excel or Google Sheets.
Stop looking at platform ROAS and start looking at MER (Marketing Efficiency Ratio).
Total Revenue / Total Marketing Spend = MER
If your MER is 5, you get $5 for every $1 spent. Now, here is the actionable part:
Take your last 12 months of data. Map your weekly spend on Facebook Ads against your weekly total revenue. Do the peaks in spend line up with peaks in revenue? If Facebook says they are killing it, but your total revenue stays flat when you double the budget, Facebook is likely just "claiming" credit for customers who were going to buy anyway (Brand Cannibalisation).
I saw this recently with a client in the Gold Coast fitness space. Their agency was bragging about a 6x ROAS on Retargeting ads. We turned the ads off for two weeks as a test. Total sales dropped by only 2%. The agency wasn't driving sales; they were just showing ads to people who were already standing at the checkout. That’s not marketing; that’s a tax on your existing customers.
The Three Pillars of Simplified MMM
To move from hindsight to foresight, you need to understand three variables that MMM uses to calculate your true ROI.
1. Adstock (The Carryover Effect)
Marketing isn't a light switch. If you run a heavy radio campaign in Brisbane this week, you won't just see sales this week. The effect "decays" over time. MMM accounts for this. It recognises that $1,000 spent today has a lingering value for the next 14 days.Actionable Tip: When evaluating a campaign, don't just look at the days the ads were live. Look at the 14-day window after the campaign ends to see the true "tail" of your investment.
2. Saturation (The Law of Diminishing Returns)
Every channel has a ceiling. If you spend $500/day on Google Ads in a niche market like "Brisbane Yacht Charter," you might get a great return. If you double it to $1,000/day, you won't double your sales because there aren't enough people searching. You'll just end up paying more for the same clicks.MMM identifies the "inflection point" where your next dollar spent is actually losing you money. Most agencies won't tell you this because they are paid a percentage of your spend. It’s one of the biggest marketing budget traps out there.
3. Base Sales (The "Hard Truth" Metric)
This is my favourite part of MMM. It calculates what your sales would be if you spent zero dollars on marketing. This is your brand equity. If your base sales are growing, your brand is getting stronger. If your base sales are flat and you're only growing through paid ads, you don't have a brand—you have a lead-buying addiction.Quick Win #2: The "Zero-Base" Test
If you want to see if your marketing is actually working, pick your weakest performing channel and turn it off for 7 days.
Look at your total business revenue (not just the platform stats). If the revenue doesn't move, or moves less than the amount you saved on ads, that channel is a zombie. Kill it. Redirect that cash into a channel that shows a clear correlation with revenue spikes.
Why Most "Dashboards" are Useless for MMM
I’ve lost count of how many Brisbane SMEs have spent thousands on fancy Looker Studio dashboards that nobody looks at. These dashboards usually just aggregate the same lying data from Facebook and Google.
If your dashboard doesn't help you make a decision, it’s just digital wallpaper. A real MMM-focused approach doesn't care about "impressions" or "CPM." It cares about incrementality.
The only question that matters: "If I didn't spend this dollar, would I still have made this sale?"
Implementing MMM: A Step-by-Step for 2026
You don't need to be a data scientist. Here is how an Aussie SME can implement a simplified version of this today:
1. Clean Your Data: Ensure your Shopify, WooCommerce, or CRM data is the "Source of Truth." Ignore the pixels for a moment. 2. Gather External Factors: MMM is powerful because it includes things outside your control. Did it rain in Brisbane last weekend? (Weather affects retail). Was it a public holiday? Put these in a spreadsheet alongside your spend. 3. Use an Incrementality Mindset: Instead of asking "What was my ROAS?", ask "What was the uplift?" 4. Test and Learn: Run a heavy campaign in one geographic area (e.g., just the Sunshine Coast) while keeping spend flat in another (e.g., Gold Coast). Compare the total revenue lift between the two. That is the purest form of MMM.
The Brisbane Context: Why Local Matters in Data
In a market like South East Queensland, seasonality is massive. We see it in our clients' data every year. A home services business in Geebung will see a massive spike in October as people prep for storm season.
If you use a generic attribution model, it will tell you your "Search Ads" are performing amazingly in October. A Marketing Mix Model will tell you the truth: "The weather is driving the demand, and your ads are just picking up the low-hanging fruit. You could actually lower your spend in October and still hit your targets because the intent is so high."
Conclusion: Stop Chasing Ghosts
Marketing Mix Modeling isn't about complex algorithms; it’s about common sense applied to data. It’s about admitting that the digital platforms aren't giving you the whole story.
By focusing on total revenue correlation, accounting for adstock, and constantly testing for incrementality, you can stop overpaying for "ghost" conversions that would have happened anyway.
Stop letting your agency hide behind platform metrics. Start looking at the relationship between your total spend and your total bank balance. That’s where the truth lives.
Ready to stop guessing and start measuring what actually moves the needle?
At Local Marketing Group, we help Brisbane businesses cut through the data noise and build marketing strategies that actually show up in the profit column. Contact us today for a no-nonsense audit of your current tracking and strategy.