Addressability

Every pitch deck has a TAM slide. Total Addressable Market — that big, round number in the top-right corner meant to signal the size of the opportunity. $50 billion. $120 billion. Sometimes a trillion. Founders present it like a weather forecast: here's how big the sky is. The implicit promise: if we capture just 1%, we'll build a massive business. The number almost never matters. What matters is addressability — the fraction of that theoretical market you can actually reach, serve, and convert with your current product, distribution, pricing, and go-to-market motion. A $100 billion TAM with 0.5% addressability is a $500 million opportunity. A $5 billion TAM with 40% addressability is a $2 billion opportunity. The second market is four times more valuable to the company that can address it, and ten times more likely to produce a fundable growth curve.

Addressability is determined by a set of filters between your product and the theoretical customer. Can you reach them? Do they know you exist? Can they afford what you sell? Is your product available in their format, language, geography, and regulatory environment? Each filter is a multiplier. If you have excellent distribution but unaffordable pricing, addressability collapses. If pricing is accessible but distribution is nonexistent, the same collapse occurs. The company's addressable market is the product of all these filters applied simultaneously — not the sum of the best one. Salesforce understood this in 1999. Enterprise CRM was a multi-billion-dollar market, but Siebel Systems could only address the Fortune 500 because every deployment required a million-dollar implementation, a team of consultants, and a year of customisation. Marc Benioff didn't grow the CRM market — he expanded its addressability. A $50-per-user-per-month SaaS product with self-serve onboarding made CRM addressable to every company with a sales team. The TAM didn't change. Addressability went from perhaps 5% to 60%.

The distinction between TAM and addressability explains most of the gap between promising markets and actual startup outcomes. Healthcare is a $4.5 trillion industry in the United States alone. The number appears in pitch decks constantly. But regulatory barriers, payer complexity, provider integration requirements, and patient behaviour patterns mean the addressable slice for any given health-tech startup is typically 0.1–1% of that number. The founders who succeed are the ones who identify the specific segment where regulatory, distribution, and pricing filters align — and build from that beachhead rather than waving at the entire market.

Addressability is also dynamic. It changes as distribution channels open, as pricing models evolve, as infrastructure develops. Stripe expanded the addressability of online payments by reducing integration from months of engineering work to seven lines of code. Shopify expanded the addressability of e-commerce by making it possible for a solo founder to launch a storefront in an afternoon. AWS expanded the addressability of server infrastructure by eliminating minimum commitments and capital expenditure. Each of these companies found that the binding constraint in their market was not demand — it was access. They didn't need to convince more people to want the product. They needed to make the product reachable by people who already wanted it.