As someone who writes about the AI industry relatively frequently for this site, there is one question that I find myself constantly asking and being asked in turn, in some form or another: What do you actually use large language models for? Today, OpenAI's Economic Research Team went a long way toward answering that question, on a population level, releasing a first-of-its-kind National Bureau of Economic Research working paper (in association with Harvard economist David Denning) detailing how people end up using ChatGPT across time and tasks. While other research has sought to estimate this kind of usage data using self-reported surveys, this is the first such paper with direct access to OpenAI's internal user data. As such, it gives us an unprecedented direct window into reliable usage stats for what is still the most popular application of LLMs by far. After digging through the dense 65-page paper, here are seven of the most interesting and/or surprising things we discovered about how people are using OpenAI today. OpenAI is still growing at a rapid clip We've known for a while that ChatGPT was popular, but this paper gives a direct look at just how big the LLM has been getting in recent months. Just measuring weekly active users on ChatGPT's consumer plans (i.e. Free, Plus, and Pro tiers), ChatGPT passed 100 million users in early 2024, climbed past 400 million users early this year, and currently can boast over 700 million users, or "nearly 10% of the world’s adult population," according to the company. Credit: OpenAI Line goes up... and faster than ever these days. Credit: OpenAI Line goes up... and faster than ever these days. OpenAI admits its measurements might be slightly off thanks to double-counting some logged-out users across multiple individual devices, as well as some logged-in users who maintain multiple accounts with different email addresses. And other reporting suggests only a small minority of those users are paying for the privilege of using ChatGPT just yet. Still, the vast number of people who are at least curious about trying OpenAI's LLM appears to still be on the steep upward part of its growth curve.