How do I build a market size slide that is credible instead of the fantasy 'we just need 1% of a billion-dollar market'?
The short answer
Never lead with a top-down '1% of a huge TAM' number, investors have seen it a thousand times and it signals lazy thinking. Build it bottom-up: number of realistic customers times what they actually pay times purchase frequency. Show your SOM (the slice you can genuinely reach in three years) as the hero number, with TAM as context above it. For India, always split India-domestic from global-from-India, because those are two different businesses with different pricing and different investors.
Go deeper, your way
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Why we picked it
It walks one worked example (a specialty foods company) all the way down the funnel and, crucially, builds SOM bottom-up from unit economics: 75 stores in year one, 200 in year two, 500 in year three, times product sales per store. That is exactly the customers-times-price-times-frequency math that replaces the '1% of TAM' hand-wave, and it shows SOM as a three-year ramp so you can present it as your hero number.
Why we picked it
Blume's annual report is the single best data-grounded read on what is actually happening in Indian internet and consumption, not what is trending on VC Twitter in San Francisco. It shows you adoption curves (UPI, quick commerce, ONDC, how few households actually shop online) so you can pressure-test whether a hyped trend has the demand base to land here. Treat it as a starting map of Indian reality, then judge your specific trend against it.
From
Blume Venturesby Sajith Pai, Anurag Pagaria and team (Blume Ventures)~180 charts
Grounds trend-spotting in real Indian adoption data (income distribution, online-shopping penetration, UPI-native monetization) instead of imported hype.
Indian startups are building a distinct playbook (micro-subscriptions on UPI Autopay, DPI rails) that has no clean US analogue, so copying a US trend directly often misses the real opportunity.
A trend can be huge in raw numbers yet thin in monetizable demand: the report repeatedly separates users from paying users.
Why we picked it
When your market slide claims a sector is heating up, this is the citeable proof point: India's VC market hit ~$16 billion in 2025 with sector-level breakdowns (fintech deal value more than doubled, SaaS up ~1.5x, verticalized quick-commerce and D2C in focus). Use it to size the capital and deal context around your SOM so an investor sees your number sitting inside a market they already believe in.
