The retention discount line
Most save offers are evaluated on how many customers stayed. The only number that decides is how many stayed who would otherwise have left.
8%
A 20% save offer held for three months breaks even once 8% of accepters were genuinely leaving. A 50% offer needs 33%.
Key takeaways
- 01A 20% save offer held for three months breaks even once 8% of accepters were genuinely leaving. A 50% offer needs 33%.
- 02Discount depth, not duration, is what punishes the offer: the targeting has to get four times more right to justify going from 20% to 50%.
- 03Gross margin does not move the break-even share at all. It moves the size of the prize, and therefore how much analysis the decision deserves.
- 04Cancellation-flow offers cannot be judged by acceptance rate, because the population that reaches the cancel button is selected, not random.
- 05The only design that answers the question is a randomised holdout held for the full window.
Romà Llambés · CEO, Markin · Reviewed 2026-09-10 · Every report is reviewed twice a year, and re-run out of cycle whenever a source it rests on changes. · Method and sources

The question
When does a retention discount keep a customer, and when does it subsidise someone who was staying anyway?
A retention discount pays only when the share of accepters who would have cancelled anyway is smaller than the break-even share set by discount depth, gross margin and remaining lifetime. At a 20% discount held three months on a 70% margin subscription with a nine-month remaining lifetime, roughly one accepter in twelve must be a genuine save. Below that, the offer subsidises loyal customers.
- Sample
- No customer data. The core result is arithmetic over four inputs: discount depth, gross margin, expected remaining months and the incremental share of accepters. It is evaluated across a grid of 5 discount depths (10% to 50%) and 3 margin levels (50%, 70%, 85%). Published subscription pricing and disclosed churn ranges from listed streaming and telecom operators are used only to bound the plausible input ranges, not to produce a result.
- Period
- Pricing and disclosure read in August 2026. The arithmetic is time-independent; the input ranges are not.
- Reviewed
- 2026-09-10Reviewed twice a year
- 8%
- At a 20% discount held for three months on a 70% margin subscription with a nine-month remaining lifetime, 8% of accepters must be genuine saves before the offer breaks even.
- 8% to 33%
- Depth punishes the offer faster than duration does: moving from 20% to 50% off, holding everything else, raises the break-even incremental share from 8% to 33%, a four-fold increase in how right the targeting has to be.
- unchanged
- Margin, not price, decides how forgiving a discount is. At 85% gross margin the break-even share for a 20% offer is 8%; at 50% margin it is unchanged.
Findings
What we found
- 018%Derived in this report
At a 20% discount held for three months on a 70% margin subscription with a nine-month remaining lifetime, 8% of accepters must be genuine saves before the offer breaks even.
The margin given away is small and immediate; the margin recovered is larger but only exists for the fraction of accepters who were actually leaving. The break-even share is the ratio between the two, and it is far lower than most teams assume, which is why shallow, short offers survive scrutiny more often than deep ones.
Do thisCompute your own break-even share from price, discount depth, discounted months and expected remaining lifetime before the next save campaign ships.
- 028% to 33%Derived in this report
Depth punishes the offer faster than duration does: moving from 20% to 50% off, holding everything else, raises the break-even incremental share from 8% to 33%, a four-fold increase in how right the targeting has to be.
A 50% offer has to be right about one accepter in three. Almost no untargeted save flow is. This is the single most useful line in the model: if a deep discount is on the table, the targeting has to be far better than the discount is deep.
Do thisIf a deep discount is on the table, improve the targeting first. Going from 20% to 50% asks the model to be four times more right.
- 03unchangedDerived in this report
Margin, not price, decides how forgiving a discount is. At 85% gross margin the break-even share for a 20% offer is 8%; at 50% margin it is unchanged.
Margin cancels out of the ratio when the discount is a percentage of price, because it scales both the giveaway and the recovery. What margin does change is the absolute size of the prize, and therefore how much analytical effort the decision deserves. Low-margin businesses should discount less because they have less to recover, not because the break-even moves.
Do thisUse margin to decide how much analysis the decision deserves, not to set a different threshold.
- 04Independent research
The failure mode is structural, not analytical: cancellation-flow offers are shown to people who reached the cancel button, a population enriched in customers who are leaving and in customers testing whether a discount appears.
Selection into the offer is not random, so the acceptance rate carries no information about incrementality. Independent research on incrementality testing finds a large share of active next-best-action programmes deliver marginal or negative lift once measured against a randomised control, and save offers are the archetype.
Do thisStop reporting acceptance rate as a save rate. Move the offer out of the cancellation flow and onto a risk score.
- 05Anonymised Markin deployments
Across Markin deployments where a save offer was moved from an untargeted cancellation flow to a risk-scored decision with a randomised holdout, the incremental share of accepters rose enough to clear break-even in most, but not all, cases.
We are deliberately not putting a single number on this. The sample is small, the bases are very different, and a mean across them would be a rounding of something rather than a finding. What travels is the mechanism: the decision moves from 'who clicked cancel' to 'who is likely to leave and likely to respond', and the second population is smaller and cheaper to serve.
Do thisHold out 10% of eligible customers for the full window, and compare the measured incremental share against your break-even line.
Charts and tables
The data
- 10% off3.7%
- 20% off8.3%
- 30% off14.3%
- 40% off22.2%
- 50% off33.3%
Depth, not duration, is what punishes the offer. Going from 20% to 50% asks the targeting to be four times more right.
- 3 months25.0%
- 6 months12.5%
- 9 months8.3%
- 12 months6.3%
- 24 months3.1%
The same offer is easy to justify on a long-lived base and hard to justify on a short-lived one.
| Discount depth | Margin given away per accepter | Margin recovered per incremental save | Break-even incremental share |
|---|---|---|---|
| 10% off | $2.10 | $56.70 | 3.7% |
| 20% off | $4.20 | $50.40 | 8.3% |
| 30% off | $6.30 | $44.10 | 14.3% |
| 40% off | $8.40 | $37.80 | 22.2% |
| 50% off | $10.50 | $31.50 | 33.3% |
| Expected remaining lifetime | Break-even incremental share |
|---|---|
| 3 months | 25.0% |
| 6 months | 12.5% |
| 9 months | 8.3% |
| 12 months | 6.3% |
| 24 months | 3.1% |
Run it on your numbers
Work out your own break-even incremental share
The same four inputs and one division used in the tables above, on your numbers. Everything runs in your browser and nothing is sent anywhere.
Break-even incremental share
8.3%
This share of accepters must be customers who would have cancelled without the offer. Below it, the offer subsidises people who were staying anyway.
- Margin given away per accepter
- $4.20
- Margin recovered per incremental save
- $50.40
Sensitivity: break-even incremental share, by discount depth and remaining lifetime
| Discount | 6 months | 9 months | 12 months | 15 months |
|---|---|---|---|---|
| 10% | 5.6% | 3.7% | 2.8% | 2.2% |
| 20% | 12.5% | 8.3% | 6.3% | 5.0% |
| 30% | 21.4% | 14.3% | 10.7% | 8.6% |
| 40% | 33.3% | 22.2% | 16.7% | 13.3% |
| 50% | 50.0% | 33.3% | 25.0% | 20.0% |
Computed at your discounted-months setting. Price and gross margin do not appear because they cancel out of the threshold. Cells above 25% ask the targeting to be right about more than one accepter in four.
Implications
What this means for the person who has to act
Head of Retention
Set the break-even share before the next save campaign ships, and treat it as the acceptance threshold. If the measured incremental share sits below it, cut depth before cutting volume: a 20% offer needs the targeting to be right one time in twelve, a 50% offer one time in three.
Finance
Ask for the break-even share alongside every save-offer business case. It is four inputs and one division, so its absence is a choice. Retained revenue reported without it is a gross number that includes the customers who were never leaving.
Data and analytics
Hold out 10% of eligible customers for the full discounted window plus the expected remaining lifetime. A holdout closed at the end of the discount measures acceptance, not retention, and will overstate the save rate.
Method
Definitions that change the answer
- Incremental save
- A customer who accepted the offer and would have cancelled without it. Not a customer who accepted and would have stayed regardless. The two are indistinguishable without a randomised holdout, which is the whole difficulty.
- Break-even incremental share
- The minimum proportion of accepters that must be incremental saves for the discount to return more margin than it gives away, over the remaining lifetime.
- Remaining lifetime
- Expected months the saved customer keeps paying after the save, at the discounted price. Deliberately conservative here: a save that lasts one billing cycle is not a save.
- Gross margin
- Contribution margin on the subscription revenue, after variable delivery cost. Content, licensing and network costs belong here. Sales and marketing do not.
Estimator
The model, written out
The break-even incremental share s*: the smallest fraction of offer accepters who had to be genuinely leaving for the offer to return more contribution margin than it gives away. Everything else in this report is a consequence of that one quantity.
Margin given away, per accepter
G = P x d x m x k
Price P, discount depth d, gross margin m, k discounted months. Paid on every accepter, incremental or not.
Margin recovered, per incremental save
R = P x (1 - d) x m x L
L is expected remaining months of paid life after the save. Deliberately priced at the discounted rate for the whole of L, which is the conservative choice.
Break-even incremental share
s* = G / R = (d x k) / ((1 - d) x L)
Price and margin cancel. The threshold depends on exactly three things: depth, discounted months and remaining life.
Programme contribution
Delta = N x (s x R - G)
N accepters, s the true incremental share measured against a randomised holdout. Delta > 0 exactly when s > s*.
What has to hold
- The discount applies for k months and the price then reverts. A permanent retention price is a different model, and a much worse one.
- A saved customer pays for L months and is not saved twice. Repeat savers are counted once, at their second acceptance.
- Gross margin m is constant over the window and the discount is a percentage of price rather than a fixed amount.
- s is measured on a randomised holdout. Nothing in the arithmetic can recover it from acceptance rates.
What breaks it
- The price never reverts. Then G = P x d x m x L and s* collapses to d / (1 - d), which is 25% at a 20% discount rather than 8%.
- The save lasts only as long as the discount, so L = k. The same 25% threshold appears from the other direction.
- The offer changes what non-accepters expect to pay. Control is then contaminated, s is biased upward and the model is measuring the wrong population.
- The discount is a fixed amount rather than a percentage. Margin stops cancelling and every price point needs its own threshold.
Method
How to reproduce this
- 01
Take the monthly price, the gross margin and the discount depth for the offer you actually send.
- 02
Compute the margin given away per accepter: price x discount depth x margin x the number of discounted months.
- 03
Compute the margin recovered per incremental save: price x (1 - discount depth) x margin x expected remaining months.
- 04
Divide the first by the second. That ratio is the break-even incremental share.
- 05
Compare it against the incremental share your holdout actually measured. If you have no holdout, you do not have the comparison, and the offer is unevaluated rather than successful.
Uncertainty
How wrong each figure could be
There is no sampling error here, because there is no sample: this is arithmetic. The uncertainty is entirely in the inputs, so every figure is published with the range it takes across the plausible input grid rather than as a point.
8% break-even at a 20% discount
Holding d = 20% and k = 3 months, across remaining lifetimes L of 6 to 15 months. The point estimate uses L = 9.
5.0% to 12.5%
33% break-even at a 50% discount
Same grid. At L = 6 the offer needs half of all accepters to be genuine saves, which no untargeted cancellation flow achieves.
20.0% to 50.0%
Effect of discounted months
At d = 20%, L = 9. Duration moves the threshold linearly; depth moves it faster than linearly.
2.8% at k = 1 to 16.7% at k = 6
Effect of gross margin
Exactly zero, not approximately. Margin cancels in s* = G / R. It scales the size of the prize, never the threshold.
zero
Robustness
What survives a different assumption
Each row changes one assumption and re-derives the threshold at d = 20%, k = 3, L = 9, m = 70%. The baseline is 8.3%.
| Change one assumption | What changes | Result | Conclusion |
|---|---|---|---|
| Gross margin halves, 70% to 35% | m is cut in half everywhere | Threshold unchanged at 8.3%. The prize halves. | Holds |
| Price doubles | P x 2 | Threshold unchanged at 8.3%. | Holds |
| The discount never reverts | k = L | Threshold rises to 25%. A three-times harder targeting problem. | Flips |
| Saved customers churn as soon as the discount ends | L = 3 | Threshold rises to 25%. Same conclusion, different cause. | Flips |
| A third of accepters would have downgraded rather than cancelled | Partial recovery credited to the save | Threshold falls below 8.3%. The offer looks better, not worse. | Holds |
| Acceptance rate triples on the same targeting | N x 3, s unchanged | Threshold unchanged. Losses triple if s < s*. | Holds |
The conclusion survives every change to price, margin and volume, because none of them enters the threshold. It is fragile to exactly two things, and they are the same thing seen twice: whether the discounted price reverts, and whether the customer stays after it does. Both are contract design questions, answerable before the campaign ships.
Limits
What this cannot tell you
- This is arithmetic, not an empirical finding. It tells you where the line is, not where your programme sits relative to it. Only a randomised holdout does that.
- It ignores second-order effects in both directions: price-anchoring damage from repeated discounting, and referral or usage value from a saved customer.
- It assumes the discount is the only thing that changed. Where a save offer is bundled with a service fix or a plan change, the attribution is no longer clean.
- The plausible input ranges come from consumer subscription businesses. Contract telecom, insurance and utilities have longer lifetimes and different answers.
Falsifiability
What would change our mind
- 01
A randomised holdout on a large base showing incremental shares above 33% on untargeted deep save offers. That would mean cancellation-flow selection is far more informative than we treat it as.
- 02
Evidence that discounted saves keep paying materially longer than undiscounted retained customers. Longer remaining lifetime lowers the break-even line for every row in the first table.
- 03
Measured price-anchoring damage large enough to dominate the ledger. That would make the break-even share necessary but no longer sufficient.
Provenance
Sources, and what each one was used for
- Independent researchBCG, Measuring Incrementality in Next-Best Action Programs (July 2026)
The finding that a large share of active programmes deliver marginal or negative lift once measured against a randomised control.
- Published pricingPublished consumer subscription pricing, streaming and telecom
Bounding plausible price points and discount depths. Not used to produce any result.
- Public company disclosureNetflix, Spotify, T-Mobile and Vodafone investor disclosures
Bounding plausible churn and remaining-lifetime ranges for the input grid.
- Derived in this reportBreak-even model
Every figure in the two tables. The formula is in the method section and can be re-run in a spreadsheet.
- Anonymised Markin deploymentsAnonymised Markin deployments
The qualitative finding on moving save offers out of the cancellation flow. No aggregate figure is published from it.
Questions this report answers
- When is a retention discount worth sending?
- How do I know if my save offer is actually working?
- What percentage of save offers go to customers who would have stayed?
- How deep should a retention discount be?
- How do I measure the incrementality of a cancellation offer?
Frequently asked
- What is the break-even incremental share of a retention discount?
- It is the minimum proportion of offer accepters who must be genuine saves for the discount to return more margin than it gives away. At a 20% discount held three months, against a nine-month remaining lifetime, it is about 8%. At 50% off it rises to about 33%.
- Why does gross margin not change the break-even share?
- Because a percentage discount scales the giveaway and the recovery by the same margin factor, so it cancels out of the ratio. Margin changes the absolute size of the prize, which is why higher-margin businesses can justify more analytical effort on the decision, not a different threshold.
- Can I measure incrementality without withholding the offer from anyone?
- No. Every alternative, pre-post comparisons, matched cohorts, propensity adjustment, absorbs seasonality and selection. A small randomised holdout, held for the full window, is the only design that answers the question, and it costs a known and usually small amount of retained revenue.
- Is this based on Markin customer data?
- The two tables are pure arithmetic and contain no customer data. Public pricing and disclosed churn ranges were used only to bound the input grid. One qualitative finding comes from anonymised Markin deployments and is labelled as such, with no aggregate figure attached, because the sample is too small and too varied to average honestly.
- What should I do with this if I already run save offers?
- Compute your own break-even share from the four inputs, then hold out 10% of eligible customers for a full window and measure the incremental share against it. If the measured share sits below the break-even line, the fix is targeting depth before discount depth.
Act on this
- PlaybookRun a retention offer before renewal without paying customers who were staying anywayPre-renewal save offers on Stripe, sized by risk instead of by list membership.
- ResearchARPU and churn, measured consistentlyMost cross-sector ARPU comparisons are comparing denominators. Once the definitions are held constant, the level differences shrink and the growth spreads do not.
- ResearchRevenue that carries marginEvery growth decision on this list raises reported revenue. Four of them raise contribution margin. They are not the same four most teams prioritise.
- GuideHow Markin measures incrementalityThe holdout design, the measurement window and the stopping rules Markin uses before any result is allowed to scale. Written to be checked.
- GuideControlled growth experiments: proving an action caused the resultEligible population, randomised control, primary metric, observation window and guardrails, and the scale, refine or stop decision that follows the readout.