Sarah Tavel - Consumer & Marketplace Investing - [Invest Like the Best, EP.168] — Summary & Takeaways · Colossus (Invest Like the Best / Business Breakdowns)

At a Glance

Sarah Tavel, a general partner at Benchmark and former early product lead at Pinterest, systematically outlines a "three-tier framework" for marketplace investing—from launching a market, tilting it, to ultimately winning—and shares investment opportunities in the consumer social space. The most impactful takeaway from the entire episode: the key to marketplace success is not GMV growth, but identifying and optimizing the "Core Action"—an action that must simultaneously create "cumulative benefits" and "increasing costs of leaving"—making the product better the more users engage, while raising the stakes of walking away.

I. The Three-Tier Framework for Marketplaces: Launch → Tilt → Win

Sarah Tavel argues that the core of marketplace investing lies in understanding the complete path from launch to tilt to win, rather than blindly chasing growth.

Level 1: Launching the Marketplace

Must start from a highly constrained market — "We don't care much about how big the initial market is, because starting small is the fastest way to achieve network effects."
Seek blue ocean opportunities: DoorDash chose the San Francisco suburbs over the city center, as there was no competition there, allowing faster validation of core assumptions.
Create liquidity through product and policy: Goat built trust via "authenticity verification," unlocking the sneaker market plagued by counterfeits.

Level 2: Tilting the Marketplace

The goal is for the flywheel to spin on its own, with customer acquisition costs declining — "you become the default option."
Two types of tilt loops:
Growth loops: buyer referrals, SEO, collaborative features (e.g., Caviar's group ordering function)
Retention loops: reputation systems improve liquidity quality — "good suppliers get more buyers, while poor suppliers naturally drop off."

Level 3: Winning the Marketplace

The key lies in how much larger you are than the second-place player — Shipstead's analysis shows that marketplace profitability is directly correlated with the size of the lead.
Case in point: Postmates invested heavily in San Francisco and New York but failed to gain a lead; the only market where it achieved leadership was Los Angeles — "If you could go back in time, you would want to put all that money and your best team into Los Angeles."

> "When you go to a market, it has to feel 'alive.' And the only way to achieve that is through extreme focus." — Sarah Tavel, quoting Bill Gurley

2. The "Participation" Revolution in Consumer Social: From Spectating to Co-Creation

Sarah Tavel is optimistic about consumer social, arguing that giants like Facebook, YouTube, and LinkedIn are being disrupted by newer, more vertical and participatory models.

Core Insight: Participation Outweighs Spectating

Internal Facebook research acknowledges that users feel worse after using the platform—they only feel better when they engage in conversations
Comparison: Fortnite represents "lean-forward" participation—"you're talking with friends and feel a sense of connection"
TikTok's success lies in "memetic" behavior—"you see what others have done, then do it yourself; everyone has a chance to go viral"

YouTube's Vulnerability

Benchmark has already invested in a company attempting to "unbundle" the beauty category from YouTube—solving the problem with a different taxonomy and approach
Analogy: Similar to how eBay was eroded by Etsy in vertical niches

LinkedIn's "Identity Problem"

LinkedIn is perfect for VCs but "useless" for professions like real estate agents
Opportunity: Create professional networks for specific industries—"real estate agents share leads among themselves, but there is no formal system to support this sharing"
Other vertical opportunities: Sales, nursing (RigUp created rich profiles for workers, effectively becoming their LinkedIn)

3. Core Action: The North Star of Product Design

Sarah Tavel argues that every digital product has a "core action"—a single behavior that best predicts user retention while simultaneously creating network effects.

Three characteristics of a core action:

1. High retention predictability: Users who complete this action are highly likely to return

2. Creates network effects: Adds value to the system (e.g., Pinterest's "pin" enriches the discovery graph)

3. Generates "cumulative benefits and increasing switching costs": The more users engage, the better the product becomes; the greater the cost of leaving

Pinterest Case

Users can do many things: like, comment, follow, browse
But "pinning an image to a board" is the core action—98% of users who complete this action return the following week
It simultaneously creates "cumulative benefits" (your boards become increasingly valuable) and "increasing switching costs" (leaving means losing a carefully curated collection)

Two test questions:

1. Would users say "the more I use the product, the better it gets"?

2. Would users say "the more I use it, the greater the loss if I leave"?

> "If you pass both tests, you have created a very sticky product." — Sarah Tavel

Counterexample: Anonymous social apps

Anonymous apps like Secret and Yik Yak have no identity, no followers, no persistence—"You can delete it, and when you open it again, the experience is exactly the same."

4. Data Strategy: From Intuition-Driven to Data-Driven, but Avoid "Empty Calories"

Sarah Tavel argues that companies require different data strategies at different stages, and the biggest pitfall is chasing "empty calorie" metrics.

Three-Stage Data Strategy:

1. Early Stage (Finding Product-Market Fit): Data is not the guide — "rely on first principles and user research, rather than being dominated by dashboards"

2. Growth Stage: Build data muscle — shift from intuition-driven to data-driven

3. Scale Stage: Focus on a single key metric — "weekly active users for your core action, track trends by cohort, everything else is secondary"

The "Empty Calories" Trap

Founders often tie their ego to a specific metric — "you want it to go up, invest effort to make it go up, report it to others"
But if it is not the most important metric, it is merely "a tax on the system"
Case in point: Postmates had massive GMV, but "if you haven't built true liquidity, it doesn't matter"

5. Pinterest’s Scaling Lessons: From "Rookie" to "Veteran"

Sarah Tavel shared key lessons from navigating hypergrowth at Pinterest, emphasizing that "not everything always goes up and to the right."

"Veteran Smoking" Analogy

When Pinterest experienced Facebook cutting off traffic and acquiring Instagram, growth shifted from exponential to linear — "You think, 'That’s it, folks.'"
But after going through several "life-or-death moments," you become like a veteran in a war movie — "When a bomb explodes, the rookie runs for cover, while the veteran just keeps smoking."
As a board member, the greatest value is being a stabilizing force when founders perceive a "minor issue" as a "life-or-death" crisis.

Organizational Restructuring Is a Necessary "Bone Reset"

"Restructuring sounds like something went wrong, but sometimes you have to break a bone to let it heal properly."
As the team expands, "defragmentation" is needed — which teams require too many cross-functional meetings? Where is communication breaking down?

Ignoring "Super User" Requests

Features demanded by super users (e.g., Pinterest users requesting "rearrange pins on boards") often serve only 0.1% of users.
Build for the "next 100 million users," not optimize for existing ones.
That feature was ultimately used by only 0.1% of users, yet its development cost was extremely high.

6. Recce Case Study: From "Trade Secrets" to Marketplace Platform

Sarah Tavel introduced her investment in London-based Recce, demonstrating how "unlocking information" can create market opportunities.

The Founder's "Trade Secrets"

Founder Ronan Given operated a hummus chain for 8–10 years and discovered that the supply chain was a key barrier to profitability
Small trick: ordering 6 lemons is cheaper than ordering 5 (because they can be purchased by the case)
Core insight: helping restaurants optimize their supply chain cost structure

Market Opportunity

Current process: restaurant owners call suppliers at 11:30 PM to leave voicemails; the next day, suppliers listen to the voicemails, transcribe them, and process the orders
Recce starts with buyers (restaurants), getting them to place orders on the platform, thereby crowdsourcing the supplier directory
Already holds a double-digit market share in London and is expanding to other cities and countries

> "These are the 'unlocking information' marketplace platforms — they aren't necessarily transactional, but they make information that was once opaque transparent." — Sarah Tavel, citing Rich Barton (Zillow founder)

Mentioned Positions

Position	Analyst View	Key Data
DoorDash	Bullish (Case Study)	Started in the suburbs of San Francisco, eventually surpassed Grubhub in market share
Grubhub	Risk Warning	Once held 60% market share, lost its lead due to self-imposed limitations (only serving restaurants capable of self-delivery)
Postmates	Risk Warning	Invested heavily in San Francisco and New York but failed to gain a lead, only held market leadership in Los Angeles
Airbnb	Bullish (Case Study)	Ranked #1 in a16z Marketplace 100; surpassed VRBO/HomeAway through "supply of different atomic units" (private listings)
Hipcamp	Bullish (Investment Target)	Analogous to Etsy vs eBay—building differentiation in the "land leasing" vertical
Goat	Bullish (Case Study)	Solved eBay's trust issue through "authenticity verification," unlocking the sneaker market
Pinterest	Hold & Observe (Former Employer)	Core action (pinning) completion rate: 98% return within the following week; previously experienced a growth crisis after Facebook cut off traffic
Recce	Bullish (Investment Target)	Double-digit market share in London, entering the restaurant supply chain market from the buyer side
Evernote	Risk Warning	Became "too heavy" with clunky collaboration features, challenged by Notion
Notion	Bullish (Case Study)	Challenged Evernote through better collaboration experience and low migration costs
TikTok	Bullish	Achieves high stickiness through "memetic" and participatory experience
LinkedIn	Risk Warning	Not applicable to certain professions (e.g., real estate agents), suffers from an "identity problem"
RigUp	Bullish (Case Study)	Creates rich profiles for workers, becoming their "LinkedIn"

Judgments Worth Remembering

1. "The success of a marketplace platform is not GMV, but liquidity." (Sarah Tavel) — Postmates had massive GMV but failed to build true liquidity; DoorDash, starting in the suburbs, reached the network effect tipping point much faster.

2. "Core actions must simultaneously create cumulative gains and diminishing losses." (Sarah Tavel) — Pinterest's "pinning" lets users build increasingly valuable boards (cumulative gains), while leaving means losing a carefully curated collection (diminishing losses); anonymous apps have neither, so they cannot retain users.

3. "Veterans keep smoking when the bomb goes off." (Sarah Tavel) — After surviving several "life-or-death" moments, staying calm about non-fatal issues is a board member's greatest value; after Facebook cut off Pinterest's traffic, it took 6–9 months to find a new growth path.

4. "Build for the next 100 million users, not optimize for existing ones." (Sarah Tavel) — Pinterest's power users demanded "rearrange pins," but only 0.1% of users ever used it; the real bottleneck was the inability to search boards.

5. "If both tests pass — the product gets better the more you use it, and the loss of leaving grows — you've created stickiness." (Sarah Tavel) — Evernote once achieved this through its search function, but the product became "too heavy," giving Notion an opening.

6. "Restructuring is sometimes a necessary 'bone reset.'" (Sarah Tavel) — As teams grow, regular "defragmentation" is needed: which teams require too many cross-functional meetings? Where is communication breaking down?

7. "Unlocking information is the core value of a marketplace platform." (Sarah Tavel, quoting Rich Barton) — Zillow (housing information), OpenTable (reservation information), and Recce (supplier pricing information) all create value by making opaque information transparent.

8. "The essence of early-stage VC is 'adopting the founder's goals as one's own.'" (Sarah Tavel, citing Kant/Christine Korsgaard) — The core of the paper "Creating a Kingdom of Ends": a friend is "someone who takes your ends as their own," which is precisely the relationship between an early investor and a founder.

Sarah Tavel - Consumer & Marketplace Investing - [Invest Like the Best, EP.168]

In plain words