How AI Companies Will Build Real Defensibility

• AI companies must run two defensibility phases sequentially, not simultaneously.
  • Phase 1 (Bailey): distribution, brand, speed — fast to deploy, temporary.
  • Phase 2 (Motte): network effects, embedding, lock-in — hard to dislodge.
• 70% of tech ecosystem value historically comes from network effects.
  • AI app layer hasn’t deployed network effects comprehensively yet.
• Google built moats sequentially: PageRank → AdWords → ecosystem embedding.
  • Groupon had distribution + virality but no real network effects — imploded.
• Cursor shows collaborative context as moat: team knowledge compounds on platform.
  • Switching cost = losing all accumulated codebase context + workflows.
• Character.AI demonstrates hub-and-spoke: creators’ characters reach millions of chats.
  • Asymmetric benefit creates internal power law; top creators locked in.
• Agent-to-agent networks are the emerging moat: shared context, cross-agent actions.
  • First movers who wire agents together will compound faster than latecomers.
• Three tests: switching cost, collaborative value multiplier, hub-and-spoke formation.

X discourse

• @garrytan: “if the harness is the product, then the moat for AI companies isn’t model access — it’s institutional knowledge encoded” (3885 likes)
• @alexandr_wang: “Distribution is the moat nobody talks about. Open-source model + pre-installed on 3B devices = game over for app store d” (2173 likes)
• @andrewchen: “Paid acquisition is a tax on your product’s defensibility. the moment you can’t out-spend the incumbents and competitors” (1035 likes)
• @gokulr: “Enterprise AI defensibility and value creation might lie in the full-stack approach to building, running and evaluating” (844 likes)
• @DJ_CURFEW: “What’s the real moat in AI? It’s not your model. It’s not your inference. It’s your HUMANS. Human engagement. Human feed” (168 likes)
• @caitlinbolnick1: “Friend told me not to use ‘first principles’ bc its over-used VC phrase… very few VCs are actually first principles th” (173 likes)

Pete Flint (NFX GP; founder Trulia, prev. partner at NFX) · 2025-07-10 · Read on nfx.com