Every business is basic maths before it is anything else. I buy something for 10 and sell it for 20. Out of that 20 I pay my staff, I pay rent, I pay for the mistakes I make along the way, and if I am lucky I save 2 and send it home. The rest keeps the machine running. More volume means more money. That part every founder understands within a week of starting up.
What took me years to understand is the other half of that equation. The 20 I made today means very little if that customer never comes back. A business that only ever sells once is not really a business. It is a transaction dressed up as one.
I learned this the hard way with Doosra College.
I founded it as a solo stint, built three digital products, trained over 300 students, ran seminars across colleges. On paper it looked like traction. Underneath it, the model was leaking. I was completely obsessed with getting the next student in the door. Lower the CAC, run one more campaign, get one more batch signed up. I got good at that part. What I never built was a reason for a student to come back, refer someone, buy the next course, stay attached to what I was building. Once they were done with me, they were done with me. I was refilling a bucket that had no bottom.
The business did not fail because the product was bad or the idea was wrong. It failed because I was optimising for the wrong number the entire time.
It took a few more years and a few more product roles, working closely with founders and investors and now Home Mechanic, for this to fully click. Across every one of these, in very different categories (fuel delivery, loan disbursal, car servicing) the businesses that were actually healthy were the ones where the customer kept coming back on their own, not the ones that were best at pulling in new customers every month. Expect for loan product where they take it for once and they are done.
At Home Mechanic this shows up in a very literal way. A car does not need servicing once. It needs it every few months, for the life of the car, as long as we give the owner a reason to trust us with it again. That repeat behaviour, not the first booking, is what turned a business doing 25 cars a month into one doing 200 plus. The first booking gets you revenue. The fifth booking from the same customer is what gets you a business.
So here is the desi logic version of it, the one I actually trust because I have tested it across enough places now. LTV, lifetime value, how much a customer is worth to you across their entire relationship with you, is the single number that decides whether you are building a business or renting attention for a quarter. Everything else, CAC, funnel conversion, even revenue in a given month, is downstream of it. You can win on low CAC for a while. You cannot win long term if LTV never catches up.
And this changes what I think the real moat is. It is not the product. Products get copied within months in most categories I have worked in. The moat is distribution, and distribution done right is really just this: how easily and how often can you bring the same customer back, through the right product experience, the right discovery, and a brand that earns a second look instead of needing to fight for a first one every single time.
Product discovery matters here more than people give it credit for. If a customer has to relearn how to buy from you every time, you are fighting friction on every single order. If the brand stands for something they remember and trust, the second purchase costs you almost nothing compared to the first. That is stickiness, and stickiness is what quietly compounds LTV in the background while everyone else is busy chasing new sign ups.
If I were starting Doosra College again today, I would not touch CAC first. I would ask a much simpler question before writing a single line of marketing copy: why would this person come back a second time, and what am I building specifically to make that happen. That single question would have changed almost every decision I made back then.
This is the framework I now carry into every product and business decision. Focus on LTV from day one, not as a metric you check in month six, but as the design principle behind the product itself. Build distribution as your actual moat. And treat every new customer not as a sale you closed, but as a relationship you now have to earn the right to keep.
Small maths, buy for 10, sell for 20. But the business that survives is the one where that customer buys from you again next month, and the month after that.