The AI ChatGPT has been a surprise sensation, even rattling Google due to its fast-rising popularity -- and now analysts at Swiss bank UBS think it is also the fastest-growing consumer app in history. UBS analysis estimates that ChatGPT had 100 million active users in January, following its launch two months ago in late November. It attracted one million users in just one week. As Reuters notes, ChatGPT's growth is a lot faster than the nine months it took TikTok to reach 100 million, and the two and half years it took Instagram to get there. In a much earlier era of the web, Google and Facebook took about five years each to reach 100 million users.
