There are various search engines for bots, such as Chatbottle, Botlist and Thereisabotforthat, for example, helping developers to inform users about the launch of new talkbots. These sites also provide a ranking of bots by various parameters: the number of votes, user statistics, platforms, categories (travel, productivity, social interaction, e-commerce, entertainment, news, etc.). They feature more than three and a half thousand bots for Facebook Messenger, Slack, Skype and Kik.
The word robot is derived from the Czech noun robota meaning “labor”, and is an accomplishment of the cubist painter and writer Josef Capek, older brother of novelist and playwright Karel Capek. The word robot first appeared in 1920 in the Karel Capek’s play “RUR” (“Rossum’s Universal Robots”) and since then this play popularized the word invented by playwright’s brother.
The term Chatbot is closely related to chat bot and chatterbot. Chatterbot is more popular in relation to chatbot who talk a lot, and is not necessary very intelligent in processing the user answers. Chat bot is used by technical people who consider the word ‘bot’ as a normal term for ‘robotised actions’, and for them ‘chat bot’ is a special kind of bot. The term Chatbot is actually the most popular amongst these three terms and has the broadest meaning.
Several studies accomplished by analytics agencies such as Juniper or Gartner  report significant reduction of cost of customer services, leading to billions of dollars of economy in the next 10 years. Gartner predicts an integration by 2020 of chatbots in at least 85% of all client's applications to customer service. Juniper's study announces an impressive amount of $8 billion retained annually by 2022 due to the use of chatbots.
“Major shifts on large platforms should be seen as an opportunities for distribution. That said, we need to be careful not to judge the very early prototypes too harshly as the platforms are far from complete. I believe Facebook’s recent launch is the beginning of a new application platform for micro application experiences. The fundamental idea is that customers will interact with just enough UI, whether conversational and/or widgets, to be delighted by a service/brand with immediate access to a rich profile and without the complexities of installing a native app, all fueled by mature advertising products. It’s potentially a massive opportunity.” — Aaron Batalion, Partner at Lightspeed Venture Partners