https://arstechnica.com/information-technology/2023/02/chatgpt-sets-record-for-fastest-growing-user-base-in-history-report-says/

On Wednesday, Reuters reported that AI bot ChatGPT reached an estimated 100 million active monthly users last month, a mere two months from launch, making it the "fastest-growing consumer application in history," according to a UBS investment bank research note. In comparison, TikTok took nine months to reach 100 million monthly users, and Instagram about 2.5 years, according to UBS researcher Lloyd Walmsley.