TL;DR
- Jahanvi Sardana challenges the overemphasis on Total Addressable Market (TAM) for startups
- Many billion-dollar companies emerged from nonexistent or invisible markets
- She urges founders to prioritize product-market fit over market sizing
- Sardana classifies TAM into three buckets: known, emerging, and invisible
- Relying too heavily on industry reports can signal shallow thinking
- Index once passed on Airbnb due to TAM miscalculation—proof that vision trumps data
TAM Isn’t Everything, Says Index Ventures Partner
At the 2025 TechCrunch All Stage event in Boston, Index Ventures partner Jahanvi Sardana made a compelling case to early-stage founders: Stop obsessing over TAM slides in your pitch decks.
Sardana emphasized that some of the world’s most transformative startups didn’t emerge from vast, existing markets. Rather, they created the very markets they now dominate.
“What was the market for search before Google?” she asked. “What was the market for cloud before Amazon?”
Instead of chasing numbers, Sardana says founders need to understand whether their product is shaped to “ride the current wave”—and today, that wave is artificial intelligence.
TAM Comes in Three Flavors: Which Are You Riding?
Sardana breaks TAM down into three distinct categories:
1. Known Market
This is a traditional, defined space with legacy players. Founders need to prove why their startup builds a better version of what’s already out there.
“Everyone brushes their teeth. Tell me why yours is a better toothbrush,” she remarked.
2. Emerging Market
A sector where adoption is underway, but mainstream traction is pending. Sardana likens this to the rise of non-alcoholic beer before it became popular.
3. Invisible Market
The most misunderstood — and the most dangerous. In this case, the market doesn’t yet exist, and founders must invent it.
“People didn’t know they needed smartphones in 2006. Now they can’t live without them.”
This type of market demands exceptional storytelling and vision-driven innovation, as users won’t know what to ask for until you show them.
When Market Size Misleads Investors
| Company | TAM Estimate at Inception | Reality | Source |
| Airbnb | Too small (missed by Index) | Became larger than top hotel brands | TechCrunch |
| Uber | Taxi market only | Created broader gig transport economy | Forbes |
| Amazon Web Services | Cloud unknown | Dominates $600B cloud infra market | Statista |
The Danger of Industry Reports and Shallow Metrics
When an audience member asked whether investors still expect a TAM slide, Sardana was diplomatic—but pointed.
“It’s okay to include it. Just don’t depend on it.”
Overreliance on third-party research can backfire, Sardana warned. Founders who outsource their market understanding to consultants or Gartner reports signal a lack of independent vision.
She encourages founders to use TAM slides as narrative aids, not crutches.
How Airbnb Changed Everything: The TAM That Lied
One of Sardana’s most candid moments came when she acknowledged that Index Ventures had passed on Airbnb early on—because its TAM looked too small.
What happened next became startup lore: Airbnb created entirely new supply and behavior in the travel industry.
“Now it’s larger than some hotel chains,” Sardana noted. “Marketplace TAMs are tricky.”
Rather than trying to size the demand up front, founders should think about unlocking supply and changing user behavior. That’s what leads to TAM expansion.
What Investors Really Want to See in a Founder
When asked what makes a startup stand out in her eyes, Sardana had a clear answer: It’s not just the market, it’s the depth of founder insight.
“We’re in the business of evaluating founders more than products or numbers,” she said.
A great pitch shows the founder knows who their customer is, what they want, and why they’ll buy—with or without perfect data.
Ultimately, founders should think of their TAM explanation not as a chart, but as a window into their ambition.
Final Thought: The Best Founders Lead with Vision
Sardana’s talk was a wake-up call to founders who treat market analysis as a checkbox. The best ideas often defy TAM logic. What matters most is how well a founder understands the problem, the customer, and the timing.
From Google and Microsoft to Airbnb and Uber, the lesson is clear: the market will follow if the product leads.
“Sometimes people don’t know what they want. You have to show them,” Sardana concluded.
