Subscriber Lifetime Value: The Only Number That Justifies a Discount

Lifetime value decides what you can afford to spend acquiring a subscriber and what discount you can afford to give. Most stores calculate it in a way that flatters the answer.

The basic formula

LTV = contribution margin per cycle ÷ churn rate per cycle

At ₹650 contribution per box and 10% monthly churn:

LTV = 650 ÷ 0.10 = ₹6,500

Two things are already wrong with that number for most stores.

Mistake one: using revenue instead of contribution

If you put the ₹1,499 box price in the numerator you get ₹14,990, which is not a number you can spend. Product, packaging, shipping, payment fees and pick-and-pack all come out first.

Use contribution margin — what is left after every variable cost of delivering one more box.

Mistake two: using blended churn

Blended churn mixes cohorts. New subscribers churn much faster than tenured ones, so a business growing quickly has a churn rate dominated by new signups, and a business that stops growing sees “churn improve” purely from mix.

Churn by cycle number is the honest input:

Cycle	Churn
1 → 2	14%
2 → 3	8%
3 → 4	5%
4+	3%

Expected lifetime is then a survival calculation, not a single division — and it is usually longer than the blended formula suggests for the subscribers who get past cycle three, and much shorter for the ones who do not.

That shape is the actionable part: it tells you your money is in getting people past cycle three.

What LTV is for

Deciding your acquisition ceiling. If LTV is ₹6,500 and you want payback within six months, your allowable CAC follows directly.

Justifying a discount. A 15% subscribe-and-save discount costs you ₹225 per box. If it converts one-time buyers to subscribers who complete six boxes instead of buying 1.4 times, it pays for itself several times over. If subscribers complete two, it does not.

Deciding what to spend on retention. If getting a subscriber from cycle 2 to cycle 4 adds ₹1,300 of expected value, spending ₹100 on onboarding content that achieves it is obviously correct.

The payback question

LTV ignores time, and time is cash. A ₹6,500 LTV realised over ten months is very different from the same number over three.

Track months to CAC payback alongside LTV. A business with good LTV and slow payback runs out of money while being technically profitable — which is the standard way subscription businesses die.

Prepaid plans compress payback dramatically, because the cash arrives at signup. Prepaid vs pay-as-you-go.

Segment it

A single LTV across all subscribers hides the useful information. Break it down by:

• Plan type — prepaid subscribers almost always have higher LTV
• Acquisition channel — some channels bring subscribers who churn immediately
• First product — the entry product predicts retention more than people expect
• Frequency chosen — subscribers who pick the frequency matching their consumption stay longer

The last one is often the most actionable finding in the whole analysis, because it is fixable with a better product page.

Frequently asked questions

How do I calculate subscription LTV?

The simplest form is average contribution margin per cycle divided by cycle churn rate. Use contribution margin, not revenue, and use cohort-based churn rather than a blended average, because blended churn mixes new and tenured subscribers and overstates lifetime.