ChatGPT
How OpenAI built the fastest-growing consumer app in history
ChatGPT went from zero to 100 million users in two months. That's not a typo. Here's how OpenAI turned a research lab demo into a consumer product that changed the conversation about AI forever.
100M
Users (2 mo)
$4B+
Revenue run rate
5 days
Time to 1M users
The Problem They Solved (Accidentally)
OpenAI didn't set out to build a consumer product. They were a research lab working on large language models. ChatGPT started as a "research preview" — basically a demo to show what GPT-3.5 could do with RLHF applied to it. The genius move? They made it free, put it on the internet, and let people play with it. Turns out, when you give everyone access to a genuinely capable AI, things go viral.
The UX Decision That Changed Everything
The chat interface was the key insight. Previous AI demos required technical knowledge — API calls, specific prompts, understanding model parameters. ChatGPT's interface was intentionally dead simple: a text box. Type anything. Get a response. The conversational format meant users already knew how to use it — they'd been texting and messaging for years. Zero learning curve.
How They Monetized
The freemium model was textbook. Free tier with GPT-3.5 to get users hooked. Plus tier ($20/month) for GPT-4, faster responses, and priority access during peak times. Then the API for developers, which is where the real B2B money lives. Enterprise tier for companies that need security, SSO, and longer context windows. They turned a research project into a multi-billion-dollar business in under a year.
The Growth Loop
ChatGPT's growth was almost entirely organic. Users would share mind-blowing or hilarious outputs on social media. Each share was a free ad that demonstrated the product's value better than any marketing could. The conversation itself was the distribution channel. OpenAI spent essentially zero on traditional marketing for the initial launch.
What They Got Wrong
Hallucinations. Data privacy concerns. The tendency to be confidently wrong about facts. The inability to cite sources (initially). Content moderation challenges. Rate limiting that frustrated users. The lack of persistent memory across conversations (fixed later). Being so successful so fast that they could barely keep the servers running. These problems haven't gone away — they've just been managed.
Lessons for Product Managers
- →Sometimes the best product launch is just... letting people try it. No waitlist, no gated access, no 12-step onboarding.
- →The interface IS the product. ChatGPT's magic wasn't the model — it was the chat box that made the model accessible.
- →Freemium works when the free version is genuinely amazing. If people aren't blown away by the free tier, they won't upgrade.
- →Your users' outputs are your best marketing. Make the product output shareable and people will share it.
- →You can ship imperfect AI if you're transparent about limitations. "ChatGPT can make mistakes" is right there on the screen.