Chatbots have been used in instant messaging (IM) applications and online interactive games for many years but have recently segued into business-to-consumer (B2C) and business-to-business (B2B) sales and services. Chatbots can be added to a buddy list or provide a single game player with an entity to interact with while awaiting other "live" players. If the bot is sophisticated enough to pass the Turing test, the person may not even know they are interacting with a computer program.
Do the nature of our services and size of our customer base warrant an investment in a more efficient and automated customer service response? How can we offer a more streamlined experience without (necessarily) increasing costly human resources? Amtrak’s website receives over 375,000 daily visitors, and they wanted a solution that provided users with instant access to online self-service.
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.
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.
Malicious chatbots are frequently used to fill chat rooms with spam and advertisements, by mimicking human behaviour and conversations or to entice people into revealing personal information, such as bank account numbers. They are commonly found on Yahoo! Messenger, Windows Live Messenger, AOL Instant Messenger and other instant messaging protocols. There has also been a published report of a chatbot used in a fake personal ad on a dating service's website.
ELIZA's key method of operation (copied by chatbot designers ever since) involves the recognition of clue words or phrases in the input, and the output of corresponding pre-prepared or pre-programmed responses that can move the conversation forward in an apparently meaningful way (e.g. by responding to any input that contains the word 'MOTHER' with 'TELL ME MORE ABOUT YOUR FAMILY'). Thus an illusion of understanding is generated, even though the processing involved has been merely superficial. ELIZA showed that such an illusion is surprisingly easy to generate, because human judges are so ready to give the benefit of the doubt when conversational responses are capable of being interpreted as "intelligent".