Ask a marketing manager how their last promotion performed and you’ll hear about entries, impressions, and social engagement. Ask them what it cost to acquire each incremental customer and the room goes quiet. That silence is costing Australian brands millions every year — not because their promotions don’t work, but because they can’t prove which ones do.
According to Marketing Week research, over a third of marketers rarely or never measure the ROI of their marketing spend. In Australia specifically, IAB research from 2026 found that 35% of marketers struggle to demonstrate incrementality from their campaigns. We’re running promotions worth hundreds of thousands of dollars and then guessing whether they worked.
This guide is for the marketing manager who’s tired of presenting entry counts to a CFO who wants dollar figures. It’s a practical framework for measuring promotional ROI that actually stands up to financial scrutiny.
Why Entry Counts Tell You Almost Nothing
The typical post-campaign report for a promotional campaign reads something like this: 42,000 entries, 3.2 million social impressions, 18% increase in web traffic during the campaign period.
None of those numbers answer the only question that matters: did this promotion generate more revenue than it cost?
Entry counts measure participation, not purchase behaviour. A competition that attracts 50,000 entries from existing customers who would have bought anyway hasn’t driven any incremental revenue. Meanwhile, a smaller promotion that converts 2,000 new customers to their first purchase might be ten times more valuable.
Entry counts are to promotions what follower counts are to social media — they feel important in the moment but they measure attention, not value.
The problem compounds over time. When you report vanity metrics, you optimise for vanity metrics. Your next campaign gets designed to maximise entries rather than revenue, and the gap between marketing activity and business outcomes grows wider with every campaign cycle.
What Does Promotional ROI Actually Look Like?
Real promotional ROI is deceptively simple in theory: net revenue generated by the promotion, minus the total cost of running it, divided by that total cost. Multiply by 100 and you have a percentage.
The formula isn’t hard. What’s hard is getting honest numbers into it.
The Incrementality Problem
Here’s where most measurement frameworks collapse. To know what revenue your promotion generated, you need to know what would have happened without it. This is the incrementality question, and it’s the single biggest gap in how Australian brands measure promotional performance.
Say you run a purchase-to-enter promotion on a product line that’s been growing at 8% year-on-year. During the promotional period, sales jump 15%. Did the promotion drive a 15% lift? A 7% lift above the baseline trend? Or was there a seasonal factor that would have driven growth anyway?
Without a control group or a credible baseline, you’re guessing. And according to a 2026 industry survey, 33% of brand marketers say they’re only measuring incrementality at a basic level, with 44% citing concerns about accuracy and 41% pointing to limited tools. This isn’t a knowledge problem — it’s an infrastructure problem.
How to Measure Your Next Promotion’s Real ROI
Here’s a practical framework that doesn’t require a PhD in econometrics or a six-figure analytics platform. It requires discipline, which is harder to buy.
Step 1: Define Your Success Metric Before You Brief Anyone
Before you write a creative brief, answer this: what commercial outcome are you trying to drive? New customer acquisition? Basket size increase? Repeat purchase rate? Category switching?
Each of these requires different measurement approaches. A promotion designed to acquire new customers should be measured on cost per new customer acquired and their subsequent purchase behaviour. A basket-builder promotion should be measured on average transaction value during and after the campaign.
Most promotional briefs define success as “generate awareness and engagement.” That’s not a commercial objective — it’s an excuse not to be measured. Define the number you’re going to report to your CFO before you design the mechanic.
Step 2: Count the Real Cost, Not Just Media Spend
Promotional ROI calculations routinely understate costs by 30–50% because they only count media spend. Your real promotional cost includes the prize pool or reward value, creative production and agency fees, platform or technology costs, permit and compliance costs (in Australia, state-based trade promotion permits alone can run $2,000–$5,000), internal team hours — yes, the three weeks your brand manager spent managing this counts — and fulfilment and logistics for physical prizes.
If your CFO ran the same numbers with fully loaded costs, would your promotion still look profitable? Do the maths before they do.
Step 3: Build a Control Group — It’s Easier Than You Think
You don’t need a randomised controlled trial to measure incrementality. You need a reasonable comparison. Three practical approaches work well for promotional campaigns.
Geographic holdout. Run the promotion in all states except one, then compare sales performance. This works well for national brands with consistent distribution across Australia.
Matched customer cohorts. If you have a customer database, compare the purchase behaviour of participants against a matched group of non-participants with similar purchase histories. Platforms like Trudy can automate this comparison by connecting promotional participation data with sales outcomes in real time.
Pre/post with baseline adjustment. Compare your promotional period against the same period last year, adjusted for known factors like distribution changes, pricing shifts, and category growth rates. This is the least rigorous option but infinitely better than no comparison at all.
The point isn’t methodological perfection. It’s having any credible baseline at all.
Step 4: Measure What Happens After the Campaign Ends
The most overlooked dimension of promotional ROI is what happens in the 90 days after the promotion closes. Did new customers come back? Did basket sizes stay elevated? Did the promotional discount reset price expectations downward?
A promotion that generates a 20% sales lift during the campaign but creates a 10% dip in the following quarter hasn’t driven growth — it’s pulled forward demand. Measuring the post-promotional period is what separates rigorous ROI analysis from a highlight reel.
Track these three post-campaign metrics as a minimum: repeat purchase rate among new customers acquired during the promotion, average transaction value in the 90 days following the campaign versus the 90 days prior, and category sales trajectory — did you return to baseline, exceed it, or dip below it?
Why Doesn’t Every Brand Do This?
If measurement is this straightforward, why do 74% of marketers report abandoning or scaling back campaigns because they lacked confidence in measuring impact?
Three reasons, all fixable.
First, incentives are misaligned. Marketing teams are often rewarded for activity — campaigns launched, entries generated, content produced — rather than commercial outcomes. When your KPIs are vanity metrics, measuring real ROI feels like a threat rather than an opportunity.
Second, data lives in silos. Promotional data sits in one system, sales data in another, customer data in a third. Connecting participation to purchase requires integration that many brands haven’t invested in. This is exactly the infrastructure gap that promotional analytics platforms like those Trevor Services builds are designed to close — connecting the dots between who entered your promotion and what they bought afterwards.
Third, measurement feels like an audit. Nobody wants to discover their campaign didn’t work. But the alternative — never knowing — is worse. The brands that measure rigorously don’t just cut underperforming campaigns. They double down on what works, and their promotional spend compounds in effectiveness year after year.
The CFO Test: Can Your Report Survive Five Minutes?
Here’s the standard your promotional measurement should meet: could you walk into your CFO’s office with this report and defend the spend?
If your post-campaign report wouldn’t survive five minutes of financial scrutiny, it’s not a report — it’s a press release for internal consumption. Marketing credibility is built one honest number at a time.
Stop measuring what’s easy. Start measuring what matters. Your promotional budget will be the last line item the CFO questions rather than the first — and that’s worth more than any entry count.
Ready to build a measurement framework that connects your promotions to commercial outcomes? Get in touch with Trevor Services.
