In 2015, the dating website Ashley Madison was hacked, 32 million users of the service were affected (and marriages on a painful scale have gone awry, ended up in many cases in court). A startling discovery in the context of this hack: (Predominantly) male users had flirted with supposedly registered female users via chat at Ashley Madison - but in fact so-called chat bots were acting (flirting) on behalf of the "virtual users": i.e. software programs that faked conversation. The example illustrates the level of maturity of this chatbot technology already in the mid-2010s.
On a side note: The company had stated that this practice of chat bots was already discontinued in 2014 in the U.S. (and worldwide one year later). The probably more astonishing fact is that Ashley Madison not only survived this scandal, but emerged with a dizzying grwoth dynamics: While the company had about 32 million users in 2015, this number has grown to about 60 million today.
Today, Chatbots are used in a variety of applications: On eCommerce, when customers inform themselves about products and the company, when they make complaints, when they request delivery. Bank customers also interact with Chatbots when they are looking for the nearest bank branch, when the bank balance is queried or for support requests. This list of use cases could be continued at will.