Sizing without a market report

You will be tempted by a headline number from a consulting report — the market is worth so many thousand crore and growing at some percent. That number is useless to you. It includes companies you will never reach, through channels you cannot use, at prices you cannot charge, and it cannot tell you whether one more small operator can make a living.

Build the estimate from the bottom instead, in a chain of numbers you can each defend. How many businesses of this type exist within the area you can actually serve? You can often count them: a district trade directory, a marketplace search, an hour walking a market, the membership list of an association. What fraction plausibly has the problem, and on what evidence from your twelve conversations? How often does it recur in a year? What would they plausibly pay, from what they told you they already spend on the workaround? Multiply, and write the assumption beside each number.

The output is not a number; it is a chain. Anyone reading it should be able to point at the link they disbelieve and say so. A sizing you cannot argue with is a sizing nobody can check, and it will not survive contact with someone who is being asked to spend their own money on it.