The most expensive mistake a first-time founder makes is spending months building a product before checking whether anyone will pay for it. Interest is cheap, but money is honest. This lesson shows you three ways to prove real demand, through pre-sales, letters of intent, and pricing experiments, before you write a single line of code.
Why "I would use this" is a trap
People are polite, and free interest costs them nothing. The only reliable proof of willingness to pay is a commitment that costs the person something real: money, a signature, or scheduled time. Design every test so that a "yes" has a price attached. If your validation involves no cost to the customer, you have measured curiosity, not demand.
Method 1: Pre-sell before you build
Put up a simple landing page describing the outcome your product delivers, add a real payment button, and ask for money or a refundable deposit. In India you can collect this through a UPI collect request or a hosted payment page from a provider such as Razorpay or Cashfree, without building the product itself. One person who pays Rs 500 today is stronger evidence than a hundred people who say they love the idea.
Keep advances fully refundable and state that clearly in writing. It is fair, it builds trust, and it lowers your risk if you cannot deliver on time.
Tax note: You do not need GST registration until your aggregate turnover crosses Rs 20 lakh for services, or Rs 40 lakh for goods, in most states, so early experiments usually sit below that line. If you are already GST-registered and collect an advance for a service, GST becomes payable at the time you receive the advance, not when you deliver, so budget for that upfront.
Method 2: Letters of intent for B2B
If you sell to businesses, a signed letter of intent (LOI) is your pre-sale. It states that a customer intends to buy your product at a stated price once you deliver defined features by a set date. Be clear about the law here: an LOI is generally not a binding contract in India. The Supreme Court has held that a letter of intent is not enforceable unless the parties' intention to be bound is evident from its terms. Treat an LOI as a strong demand signal and a credibility tool for investor conversations, not as guaranteed revenue.
To make an LOI meaningful, insist on specifics: the exact problem being solved, the budget already allocated, the name of the decision maker, and a target start date. Vague enthusiasm printed on a letterhead is still vague.
Method 3: Run pricing experiments
Do not guess your price. Test it. Show a real "Buy now at Rs X" button and measure how many people actually click through and pay at each price point.
- Run the same offer at two or three prices with different audiences, then compare conversion. You are hunting for the price where enough people still commit, not the highest number anyone will tolerate.
- Ask buyers two questions: at what price does this feel too expensive, and at what price does it feel so cheap you would doubt its quality. The gap between those answers reveals your acceptable range.
Turning signals into a decision
Set a target before you start, for example, "10 paid pre-orders or 3 signed LOIs within three weeks." Clearing the bar means you build. Missing it means you change the offer, price, or audience before you spend money on engineering.
You do not need to incorporate a company just to test demand. Once you have real traction and revenue, register a Private Limited company and, if eligible, apply for free DPIIT Startup recognition, which is open to entities up to 10 years old with turnover under Rs 200 crore in any financial year and unlocks tax and compliance benefits. Every rupee collected and every signature gathered before you build is proof, not opinion. Prove demand first, then write code.