Adyen

Adyen exhibits preferential attachment dynamics at payment infrastructure scale. The Dutch fintech processed €1.29 trillion in transaction volume during 2024 (up 33% YoY), converting network effects into 50% EBITDA margins and €2.0 billion revenue through unified commerce platform architecture. Unlike legacy payment processors that aggregate third-party services, Adyen builds end-to-end infrastructure—authorization, fraud detection, settlement, reconciliation—creating switching costs that compound with transaction volume.

This architecture mirrors mycelial network expansion: each new merchant connection (especially large platforms like Uber, Spotify, Microsoft) increases network value for subsequent nodes. "Adyen for Platforms" demonstrates this mechanism—28 platforms processing €1B+ annually now serve 145,000 SMBs (up from 88,000 in 2023), with each sub-merchant deepening the infrastructure moat. The company maintains 61% operating margins while staying debt-free with €4.6 billion cash reserves, reinvesting growth into geographic expansion (India payments license 2024, 40%+ revenue now outside Europe).

The metabolic scaling law applies: Adyen's infrastructure costs grow sublinearly with transaction volume (Kleiber's Law), enabling margin expansion as processed payments increase. The company's 23% revenue growth with 34% EBITDA growth reflects this biological principle—network organisms achieve efficiency through scale, not through cost reduction.