A 15% subscription price increase does not produce 15% more contribution. Some customers leave, some switch plans, and existing subscribers reach the new price at different times.
The useful structure keeps those responses visible. It also gives you a clear threshold: how much customer loss can the business absorb before the price increase stops paying?
This worked example takes a music-learning app through that calculation, then introduces a plan change that reverses the first answer.
The case: raise annual prices by 15%
A music-learning app wants to increase contribution over the next year. Its founder is considering a 15% increase in the annual subscription price.
Existing annual subscribers keep their current price until renewal. New customers see the new offer when they join. The app also has a cheaper basic plan, and service costs differ by plan.
Confirm what the founder means by next-year contribution. Contribution earned from service delivered during the calendar year and cash collected from annual subscriptions are different views. A December annual payment covers service extending into the following year.
For the first calculation below, compare a cohort's full twelve-month renewal period. Later, place the cohorts on the company's actual calendar. That keeps the unit economics simple without losing the timing question.
Structure customer response before multiplying revenue
A strong opening would be:
“I would separate existing subscribers reaching renewal from new customers. For each group, I would estimate who buys at the new price, who moves to a cheaper plan and who leaves. I would then calculate contribution after each plan's service costs, and map the result to renewal dates so we capture only the benefit that falls within next year.”
I would start with existing renewal cohorts because the app can usually identify their current prices, usage and renewal dates. Their behaviour also provides a concrete test of the proposed increase.
Do not assume every cancellation is caused by pricing. Some users would leave at the old price because they have stopped practising, achieved their goal or found another learning method. Your comparison needs an unchanged-price baseline.
Quick Structuring Drill
A trail-mapping app plans to raise its premium annual price. Before forecasting revenue, the team wants to understand how each type of renewing subscriber responds.
- Premium today
- £50 contribution per year
- Premium after rise
- £62 contribution per year
- Basic plan
- £20 contribution per year
Compared with keeping the old price, how does each outcome change contribution?
Establish contribution at the old price
Consider 1,000 premium subscribers due to renew together. The case supplies these assumptions:
| Measure | Current offer |
|---|---|
| Annual price | £120 |
| Variable service cost per renewed subscription | £30 |
| Expected renewal rate at the current price | 80% |
Contribution per renewed subscription is £120 − £30 = £90. At an 80% renewal rate, 800 people renew, producing:
800 × £90 = £72,000 of contribution.
Fixed product and company costs are unchanged in this comparison. Any additional campaign or support costs caused by the price change would need to be deducted separately.
That £72,000 is the number the proposed offer has to beat. Comparing the new price against all 1,000 current users would assume away the existing renewal loss.
Find how much renewal loss the increase can absorb
A 15% increase takes the annual premium price to £138. With the same £30 variable service cost, contribution becomes £108 per renewed premium subscription.
If 75% renew, the new offer generates:
750 × £108 = £81,000, which is £9,000 more than the unchanged-price baseline.
The five-percentage-point reduction in renewal is affordable on these assumptions. To find the threshold, divide the baseline contribution by the new contribution per customer:
£72,000 ÷ £108 = 666.7 renewals.
The app needs at least 667 premium renewals out of 1,000, roughly a 66.7% renewal rate, to match or exceed the baseline before extra implementation costs.
That is also 83.3% of the 800 people expected to renew at the old price. State which denominator you mean. “We can lose a third of customers” would be misleading when the baseline already assumes some non-renewal.
Quick Case Math Drill
A bike-servicing membership pays mechanics for the services included in each member's annual plan. It is considering a higher fee for members at their next renewal.
- Annual fee
- £100 rising to £125
- Service cost per member
- £25 a year, unchanged
- Renewal at old fee
- 80% of members due
What minimum renewal rate keeps contribution equal to the old fee's?
Now let customers switch to the cheaper plan
The interviewer reveals that the forecast of 750 renewals includes 500 premium renewals and 250 basic renewals. Basic costs £80 a year to buy and £20 per subscriber to serve.
The retained headcount has not changed, but its economics have:
| Renewed plan | Subscribers | Contribution each | Total |
|---|---|---|---|
| Premium | 500 | £138 − £30 = £108 | £54,000 |
| Basic | 250 | £80 − £20 = £60 | £15,000 |
| Combined | 750 | £69,000 |
The proposal now produces £3,000 less contribution than the £72,000 baseline. Looking only at a 75% renewal rate would have missed the reversal.
This does not prove the basic plan is bad. Some of its customers might otherwise cancel altogether. It means the decision needs a plan-level response forecast, including what those customers would do under the alternative offer.
Analyse customer value, packaging and service cost together. Use the case arithmetic to test whether this particular mix pays.
Bring renewal dates back into the annual plan
The cohort example compares twelve months after renewal. The founder asked about next year.
If the £9,000 full-year improvement from the all-premium scenario applies to a cohort renewing on 1 July, only six months of its service contribution fall into that calendar year. Under an even service pattern, that is £4,500, before any other changes.
An annual cash receipt at renewal would follow a different timing pattern. Keep the view the client requested consistent across all options.
For the total plan, group existing subscribers by renewal month and current offer. Model new-customer conversion separately, including acquisition spending and when those customers start. Do not apply the renewal response of established learners to people who have never used the app.
Turn the threshold into a practical test
A useful test measures paid behaviour after the new offer is communicated: premium renewal, basic renewal, cancellation, realised contribution and support demand. Separate low-usage subscribers from engaged learners so you can see where the offer loses value.
Explain the new price, when it applies and what each plan includes. The timing is part of the commercial design. Netflix's price-change help page, for example, connects notification to the affected billing date; it illustrates why an announcement date alone does not describe when revenue changes.
On the final case figures, I would not recommend rolling out the 15% increase unchanged. I would test a smaller increase or revised package, using £72,000 per comparable renewal cohort as the contribution benchmark and including migration costs.
The useful conclusion is precise: the higher premium margin can support some customer loss, but the forecast move into basic makes this proposal worse than holding price.
Try the pricing structure drill, or use the pricing framework to explore the wider set of pricing decisions.
Structure drill
Would your case structure convince an MBB interviewer?
Industrial Hardware Pricing Pressure
Present your approach aloud. Get feedback on how you break down the problem, prioritise your analysis and explain your structure.
Frequently asked questions
Setting up the problem
Does a 15% price rise mean 15% more contribution?
No. Some customers leave, some switch to cheaper plans, and existing subscribers reach the new price only at renewal. Per retained premium subscriber, contribution actually rises from £90 to £108, a 20% gain, because the £30 service cost stays fixed. The total depends on how many renew and on which plan.
What should I clarify with the founder before calculating anything?
Confirm what 'next-year contribution' means and which period it covers. Existing annual subscribers keep their current price until renewal, so some benefit may fall outside the year. Also note that a cheaper basic plan exists and that service costs differ by plan, because both affect the result.
How should I structure customer response to the price rise?
Separate existing subscribers reaching renewal from new customers. For each group, estimate who buys at the new price, who moves to the cheaper plan and who leaves. Then calculate contribution after each plan's service costs and map results to renewal dates, so you count only the benefit falling within next year.
Renewals and the break-even point
What is baseline contribution at the old price?
For 1,000 premium subscribers renewing together at £120, each renewal contributes £90 after the £30 service cost. At an 80% renewal rate, 800 renew, giving £72,000. Any new offer must beat this figure, so establish it before modelling the price increase.
Is a drop in renewal from 80% to 75% affordable?
On these assumptions, yes. At £138, each renewed premium subscription contributes £108, so 750 renewals generate £81,000. That is £9,000 more than the £72,000 baseline despite 50 fewer renewals. The higher margin per retained customer more than covers the losses, provided every renewal stays on premium.
How do I find the maximum renewal loss the price rise can absorb?
Divide baseline contribution by the new contribution per renewal: £72,000 ÷ £108 gives roughly 667 renewals. Below that, the increase stops paying. In rate terms, renewals can fall from 80% to about two-thirds of the cohort before contribution drops below the unchanged-price baseline, assuming all renewals stay premium.
When customers downgrade
What changes if some renewing customers switch to the basic plan?
The answer can reverse. If the 750 renewals split into 500 premium and 250 basic, premium contributes £54,000 and basic, at £80 less £20 service cost, contributes £15,000. The total of £69,000 is £3,000 below the £72,000 baseline, even though the number of renewals is unchanged.
Why does the same number of renewals produce less contribution?
Because each basic subscriber contributes £60, against £108 for premium. Headcount retention hides a shift towards the lower-margin plan. That is why the structure tracks plan changes alongside cancellations: a forecast that counts only retained subscribers can look successful while contribution is falling.
Does the break-even of about 667 renewals still apply once downgrades exist?
Not on its own. That threshold assumes every renewal stays on premium at £108. Once some customers move to basic, the average retained subscriber is worth less, so the business needs more renewals to break even. Recalculate using the expected plan mix rather than the all-premium figure.
Timing and testing
How does renewal timing affect next year's figure?
Only the benefit falling within the year counts. If the £9,000 full-year improvement belongs to a cohort renewing on 1 July, only six months fall into that calendar year. Under an even service pattern that is £4,500, so a cohort-level gain overstates the annual result unless renewal dates are mapped.
Would the answer differ if I measured cash rather than contribution earned?
Potentially, yes. An annual subscription produces a cash receipt at renewal, which follows a different pattern from contribution earned evenly across the service period. Agree with the founder which measure 'next year' refers to before allocating a cohort's benefit across the months.
How should the price increase be tested in practice?
Measure paid behaviour after the new offer is communicated: premium renewals, basic renewals, cancellations, realised contribution and support demand. Separate low-usage subscribers from engaged learners to see where the offer loses value. Compare the results with the renewal threshold to judge whether the increase pays.
Does the way the price change is communicated matter?
Yes, timing is part of the commercial design. Explain the new price, when it applies and what each plan includes. Communication also determines when the new price starts affecting renewals, which in turn shapes how much of the benefit falls within the year the founder cares about.