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Chapter Two · Adoption

Adopted faster than any
technology in history.

The personal computer took twenty-two years to reach seventy percent of US households. ChatGPT crossed fifty-four percent of US adults in thirty-three months.

A joint working paper from economists at the St. Louis Fed, Vanderbilt, and Harvard compared generative-AI adoption to every consumer technology in the modern record. Their conclusion, stated without hedging: “relative to the introduction of the first mass-market product, genAI has been adopted at a faster pace than both PCs and the internet.”
Personal Computer
17yrs
to 40% US adoption
Internet
4yrs
to 40% US adoption
Smartphone
6yrs
to 40% US adoption
Generative AI
2yrs
to 40% US adoption
US Adoption S-Curves · Years from mass-market launch

Race the technology curves.

0%20%40%60%80%100%year 0year 5year 10year 15year 2040% ADOPTION
NoteGenerative AI series stops at the last measured data point (Aug 2025 · 54.6% per St. Louis Fed / NBER w32966). No projection beyond measured data.

§2.1The numbers that land.

5 days

For ChatGPT to reach one million users. Netflix took 1,277. Twitter took 730.

Source · Sam Altman, Dec 5 2022
54.6%

of US adults aged 18–64 using generative AI as of August 2025 — faster than PC or internet at equivalent points.

Source · Bick, Blandin & Deming · St. Louis Fed / NBER w32966
900M

Weekly active ChatGPT users as of February 2026, with approximately 50 million paying subscribers.

Source · OpenAI · TechCrunch, Feb 27 2026
Primary sources: Bick (St. Louis Fed), Blandin (Vanderbilt), Deming (Harvard), “The Rapid Adoption of Generative AI,” NBER Working Paper 32966; St. Louis Fed “State of Generative AI Adoption” (Nov 2025 update, methodology revision); Pew Research (Jun 25 2025); McKinsey Global Survey on AI (Nov 2025 edition). Historical adoption curves from Our World in Data and the US Census CPS.