An exam-prep subscription company has a customer acquisition cost of Rs 1,800, annual revenue per learner of Rs 3,200 at 65% gross margin, and 55% of learners renew each year. Does it have a competitive advantage and barriers to entry, and can its revenue growth last?

The unit economics work, but they show a business buying customers, not a moat. A learner yields Rs 2080 of gross profit a year and stays about 2.2 years, so lifetime gross profit is about Rs 4,622, 2.6 times the Rs 1,800 acquisition cost. A moat would show as renewals rising and acquisition cost falling; neither is happening. Growing 30% a year with 45% churn means replacing three quarters of the base each year, which eats about 65% of gross profit, so the growth is bought and lasts only while the advertising does.

Start with one learner, as you would with one customer of a tuition centre: what the centre spends on flyers to get a student in the door, what it earns from her each year, and how many years she stays. Each learner brings Rs 3,200 of revenue at 65% margin, Rs 2080 of gross profit a year, and with 45% leaving each year stays an average of 1 / 0.45 = 2.22 years, so lifetime gross profit is about Rs 4,622, 2.6 times the Rs 1,800 it cost to win her. Discounted at 12% the ratio is 2.3; the first year alone nearly repays the cost, with payback at about 10 months. These are healthy numbers for a subscription business, and they are the easy part of the question.

In two places, and only two. A company that customers prefer keeps more of them: renewal rises, and lifetime value with it. A company that customers seek out spends less to find them: referrals and brand bring learners in, and acquisition cost falls. Shikshavani's renewal is 55% and its acquisition is almost entirely paid advertising, so on the numbers it has no visible moat; it has a product people buy and a marketing machine that finds them. Barriers to entry look low too: recorded lectures and question banks are cheap to produce, the advertising auction is open to any rival with money, and a competitor bidding for the same keywords raises everyone's acquisition cost. The honest reading of exam prep is that some churn is structural, since a learner who passes her exam leaves, so the moat test is whether the company can move her to the next exam, which would show in the cohort data.

Count what growth costs. With 45% of learners leaving each year, growing the base 30% means adding 75 new learners for every 100 existing ones. That costs 0.75 x Rs 1,800 = Rs 1,350 per existing learner, against Rs 2080 of gross profit from that learner: 65% of gross profit goes to buying the next year's growth, leaving Rs 730 for content, technology, administration and profit. That is a treadmill, and it speeds up: the pool of exam candidates is finite, so each extra learner costs more to find, and any rival in the auction raises the price. At 70% renewal the same growth would take 52% of gross profit. Growth lasts if renewal rises or acquisition cost falls; if neither moves, it lasts as long as the advertising budget.

Close with a view and what would change it. The company has sound unit economics and no demonstrated moat, and its growth is purchased. That makes it a business worth owning at a price that assumes slower growth, not at a multiple that assumes the 30% continues. The evidence that would change the view: cohort charts showing renewal rising for later cohorts, a growing share of new learners arriving by referral or direct search rather than paid ads, and acquisition cost falling while the base grows. The limit of the analysis: a constant renewal rate hides the difference between learners who pass and leave happy and those who leave unhappy, and the cohort data is what separates them.