Common threads through 25 years of VC investing

AI startups fail because founders obsess over models, not company building. Harrison Miller is a former VP/GM from Amazon.com’s early years, and former MD of Summit Partners, which over 40+ years has invested $40B in more than 550 tech companies. He explains why execution, not algorithms, determines survival.
About the speaker

Harrison Miller

Summit Partners

 - Summit Partners

Harrison Miller is Senior Advisor & Former Managing Director at Summit Partners

  • Part 1 Common threads through 25 years of VC investing

Episode Chapters

  • 03:41: Amazon's brutal inventory reality

    Toys are like rotting fruit in January—$60 million worth of stranded inventory that devalues quickly while competitors with no physical risk eat your lunch.

  • 06:43: Jungle gyms break distribution models

    Moving from CDs to playsets means paying upfront in February for products you can't return, fundamentally breaking the cash flow that made media businesses work.

  • 11:13: Unit economics expose everything

    The first-ever analysis of what it actually costs to receive, shelve, pick, pack and ship revealed they'd never make money at scale—insight that killed eToys.

  • 12:02: Marketplace born from desperation

    Toys "R" Us owned the Barbies, Amazon owned the website—flipping from burning $60 million yearly to making $60 million by not owning inventory.

  • 18:29: Investing has no scoreboard

    The hardest transition from operator to investor is not knowing if you're good at this job for five to ten years while competitive people crave immediate feedback.

  • 20:54: AI bubbles demand fundamentals

    Building enduring companies in bubble environments is actually harder due to pace and hype—the fundamentals of talent, culture and decision-making become more critical, not less.

  • 21:36: People problems trump everything

    Every good investment decision and every poor one came down to A-level people versus B-plus talent—high mean talent with low variance around that mean wins.

  • 23:36: Character beats capability in foxholes

    Courage, grit and dedication to mission predict success better than pure intelligence when companies face their darkest moments and need midnight calls.

  • 28:27: Democracy is your business platform

    Every business and life is built on the platform of rights-based, rules-based democracy—when that platform goes wobbly, everything built on top is at risk.

  • 32:45: Strong men kill i ovation

    Countries that backslide to strongman rule see businesses focus on favor from the top rather than product quality and strategy—Hungary's economy crashed to bottom decile under Orban.

Episode Summary

  • Why 95% of AI Startups Are Building on Quicksand

    The Brutal Reality

    Harrison Miller, who helped build Amazon's first marketplace and invested in 550+ tech companies at Summit Partners, drops an uncomfortable truth: "Building an AI startup is 95% company building and 5% AI." While founders obsess over model performance and GPU clusters, they're ignoring the fundamentals that determine whether any company survives. Miller's track record—from launching Amazon's first non-book category to creating what became AWS—gives him unique authority to call bullshit on today's AI hype cycle.
  • The Post-Check Playbook

    Lesson 1: Your Unit Economics Will Kill You Before Your Competition Does

    Miller learned this the hard way at Amazon. After successfully launching the toy category and capturing market share, he found himself sitting on $60 million of rapidly depreciating inventory. "Toys in January are like rotting fruit," he recalls. The breakthrough came from doing something most AI startups skip: actual unit economics analysis. They discovered the brutal math—receiving, shelving, picking, packing, and shipping individual items would never be profitable at scale. This led to the Toys "R" Us partnership that flipped their business from burning $60 million a ually to making $60 million. The parallel to AI is stark: most startups are burning cash on compute and data acquisition without understanding their true cost structure.
  • Lesson 2: Talent Variance Is Your Biggest Risk

    "The reason Amazon was so successful is that the mean level of talent there was very high and the variance around the mean very low." Miller's investing career reinforced this truth—every good decision came down to A-players versus B-plus players who looked good on paper. In today's bubble environment with inflated valuations and crazy compensation, the temptation is to hire fast. But Miller warns that character matters as much as capability: "It's how people perform in the foxhole when it's really going poorly that can be the make or break."
  • Lesson 3: Platform Shifts Create False Confidence

    When Amazon's stock went from 20 to 120 in three months, Jeff Bezos constantly reminded the team: "You are not six times smarter than you were two months ago." Two years later, the stock hit 6. Miller lived through both extremes, watching as "all my staff's moms were calling, saying 'Go work at Boeing.'" Today's AI entrepreneurs face the same dynamic—$100 billion in venture investment last year alone, up 80%. The bubble creates an illusion of progress that masks fundamental business challenges.
  • What Actually Works vs. VC Mythology

    Miller's framework for building in bubble environments cuts through the noise. First, embrace constraints through clear principles—Amazon's six core values weren't suggestions, they were hiring and firing criteria. Second, focus on creating new business models, not just applying new technology. The Toys "R" Us deal wasn't about better algorithms; it was about fundamentally rethinking who owns inventory risk. Third, prepare for the reversal. "For every poorly researched article about what geniuses we are, there's going to be a poorly researched article about what idiots we are. Neither are true."
  • The Unfair Advantage

    The real insight from Miller's 25-year journey from operator to investor isn't about AI at all. It's about recognizing that technological revolutions—whether internet, mobile, or AI—follow predictable patterns. The wi ers aren't those with the best technology but those who nail the fundamentals: rigorous talent selection, honest unit economics, and the discipline to build sustainable business models when everyone else is chasing the next shiny object. As Miller puts it: "If the idea is a quick flip, yeah, there's some opportunities there. But if the idea is to build an enduring, great company, in many ways it's actually harder because of the pace and the hype and the frenzy of it all."
  • Part 1 Common threads through 25 years of VC investing
About the speaker

Harrison Miller

Summit Partners

 - Summit Partners

Harrison Miller is Senior Advisor & Former Managing Director at Summit Partners

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    Part 1Common threads through 25 years of VC investing

    AI startups fail because founders obsess over models, not company building. Harrison Miller is a former VP/GM from Amazon.com’s early years, and former MD of Summit Partners, which over 40+ years has invested $40B in more than 550 tech companies. He explains why execution, not algorithms, determines survival.