Somewhere in most cashback planning meetings, the offer gets costed at face value. A $100 cashback on a $1,000 appliance goes into the spreadsheet as $100 a unit, the same as a discount would. Anyone who has processed the claims knows that’s not how it plays out — a meaningful share of the people who buy on the promise of a cashback never get around to claiming it. The gap between the two numbers has a name, decades of research behind it, and more influence over a cashback budget than any other single figure. It’s also the number most likely to be missing from the plan.
What is slippage in a cashback promotion?
Slippage is the percentage of eligible buyers who never claim the cashback they’re entitled to. Because unclaimed cashbacks cost the brand nothing, a cashback’s true cost is its face value multiplied by the redemption rate — not the face value itself — which is why a cashback almost always costs less than a discount of the same headline amount.
The industry sometimes calls the same thing “breakage”, borrowing the term from gift cards. Either way, it isn’t a loophole and it isn’t something to engineer. The receipt goes in the bin, the claim window closes, the form gets abandoned halfway — none of it because you designed it that way. Your job is to forecast it accurately, not farm it. And forecasting it is harder than most planning meetings assume, which is the part of this that actually deserves your attention.
The arithmetic: what a cashback actually costs
A discount reaches 100% of buyers, every time, whether they noticed the promotion or not. A cashback reaches only the buyers who claim — and claim rates sit well below what most planners assume. The best public data is a 2023 study by Tremendous and The Decision Lab, which found digital rebates of $20 or less were claimed only around 38% of the time, rising to roughly 50% for $50 rebates. Run that through the spreadsheet: at the study’s observed rate, a $50 cashback costs about $25 a unit in redemptions, where a $50 discount costs the full $50 on every sale. Same headline offer to the shopper, half the redemption cost to the brand.
The academic literature explains why the gap is so persistent. Scott Gilpatric’s Marketing Science paper on slippage in rebate programs ties it to present-biased preferences: the purchase happens now, the claiming effort comes later, and later is where good intentions go to die. The same study data shows claim rates climbing as the money gets bigger — which is why the cashbacks running in the Australian market right now cluster in high-ticket categories: Sony offering up to $1,000 on selected cameras and lenses, LG up to $300 on TVs through Betta, OM System (the old Olympus camera business) up to $500. Nobody runs a $5 cashback on purpose.
How do you forecast a redemption rate?
A redemption rate is a forecast, not a constant, and it moves with five things: the value of the offer relative to the purchase, the friction in the claim process, the length of the claim window, how quickly the money arrives, and who the buyer is. A $15 cashback claimed through a clunky form with a 30-day window and a six-week EFT payout will slip enormously. A $300 appliance cashback claimed by scanning a QR code, uploading a receipt and receiving a PayID payout inside a day will not. Every choice you make about the claim journey moves the rate — which means slippage is partly a design outcome, and you should know which way your design is pushing it before you commit a budget number.
Here’s how wrong the forecasts get, from our own claim queues at Trevor Services. Two recent appliance bundle cashbacks we processed: one was budgeted for roughly 1,700 claims and closed under 900 — 52% of forecast. The other was budgeted for about 2,600 and also closed under 900 — 35% of forecast. Both promotions came in far cheaper than planned, which sounds like good news until you notice that the same forecasting error in the other direction would have blown the accrual by two to three times. If operators with campaign history on hand can miss by that margin, a redemption rate pulled from instinct in a planning meeting isn’t a forecast, it’s a guess with a spreadsheet cell.
Which is why this becomes a finance conversation, not just a marketing one. The redemption forecast sets the liability you accrue, and a promotion that out-redeems its forecast doesn’t fail loudly — it fails in the accruals, months later, when finance asks why claims are still coming in. The honest approach is to budget at a conservative redemption rate, track actual claims weekly against the forecast, and re-accrue as the pattern emerges; the first fortnight of claims data usually tells you where the campaign is heading. For brands that can’t carry the tail risk of over-redemption, sales promotion insurance exists precisely to cap it: you pay a fixed premium and the insurer wears the variance. The brands that get burned by slippage aren’t the ones using it — they’re the ones who never put a researched number on it. And the best predictor of your next claim rate isn’t the planning meeting’s instinct; it’s what similar offers actually did, which is exactly the history worth consulting before you commit the budget line.
The line you can’t cross: slippage and the ACCC
There’s a version of this thinking that tips into misconduct, and it’s worth being blunt about where the line sits. Budgeting for the fact that some people won’t claim is legitimate. Designing the claim process so that people can’t claim — burying conditions, shrinking windows, adding gratuitous steps — is not, and it’s squarely in the regulator’s sights. The ACCC’s guidance on cash back offers is plain: conditions and limitations must be clear to the consumer before purchase, and a business that offers a rebate must intend to honour it as offered. The regulator has been warning brands about undisclosed cashback conditions for years, and a promotion that quietly relies on entrapment rather than forgetfulness is a complaint waiting to be lodged.
The practical test is the one we call the Insult Threshold in The Shelf Truth, our promotional strategy guide: if the effort of claiming isn’t worth the reward, you haven’t saved money, you’ve insulted a customer who did exactly what your advertising asked. High slippage driven by a low-value offer or a hostile claim process isn’t a budget win — it’s a signal the promotion shouldn’t have run in that shape at all. The cashbacks that work are the ones where claiming is easy, payment is fast, and the slippage that remains is the genuine, unforced kind.
Forecast it, don’t farm it
Slippage is the reason a cashback can deliver a $100-off message for materially less than $100 a unit. It’s also the least reliable number in the plan — our own claim queues show forecasts missing by half — which means it deserves the most scrutiny, not the least. Put a researched number on it before launch, design the claim journey deliberately rather than accidentally, track actuals weekly, and stay on the right side of the ACCC’s line. If you’re building a cashback budget and want to pressure-test the redemption assumptions against real campaign history rather than instinct, we’re happy to talk it through. The slippage will take care of itself — it always does. The forecast won’t.
