We then ran a second test with a very specific topic aimed at answering very specific questions that a small segment of their audience was interested in. There, the engagement was much higher (97% open rate, 52% click-through rate on average over the duration of the test). Interestingly, drop-off went wayyy down there. At the end of this test, only 0.29% of the users had unsubscribed.
As IBM elaborates: “The front-end app you develop will interact with an AI application. That AI application — usually a hosted service — is the component that interprets user data, directs the flow of the conversation and gathers the information needed for responses. You can then implement the business logic and any other components needed to enable conversations and deliver results.”

In a procedural conversation flow, you define the order of the questions and the bot will ask the questions in the order you defined. You can organize the questions into logical modules to keep the code centralized while staying focused on guiding the conversational. For example, you may design one module to contain the logic that helps the user browse for products and a separate module to contain the logic that helps the user create a new order.
More and more companies embrace chatbots to increase engagement with their audiences in the last few years. Especially for some industries including banking, insurance, and retail chatbots started to function as efficient interactive tools to increase customer satisfaction and cost-effectiveness. A study by Humley found out 43% of digital banking users are turning to chatbots – the increasing trend shows that banking customers consider the chatbot as an alternative channel to get instant information and solve their issues.
For example, ecommerce companies will likely want a chatbot that can display products, handle shipping questions, but a healthcare chatbot would look very different. Also, while most chatbot software is continually upping the AI-ante, a company called Landbot is taking a different approach, stripping away the complexity to help create better customer conversations.
In 1950, Alan Turing's famous article "Computing Machinery and Intelligence" was published, which proposed what is now called the Turing test as a criterion of intelligence. This criterion depends on the ability of a computer program to impersonate a human in a real-time written conversation with a human judge, sufficiently well that the judge is unable to distinguish reliably—on the basis of the conversational content alone—between the program and a real human. The notoriety of Turing's proposed test stimulated great interest in Joseph Weizenbaum's program ELIZA, published in 1966, which seemed to be able to fool users into believing that they were conversing with a real human. However Weizenbaum himself did not claim that ELIZA was genuinely intelligent, and the Introduction to his paper presented it more as a debunking exercise:
In sales, chatbots are being used to assist consumers shopping online, either by answering noncomplex product questions or providing helpful information that the consumer could later search for, including shipping price and availability. Chatbots are also used in service departments, assisting service agents in answering repetitive requests. Once a conversation gets too complex for a chatbot, it will be transferred to a human service agent .
The evolution of artificial intelligence is now in full swing and chatbots are only a faint splash on a huge wave of progress. Today the number of users of messaging apps like WhatsApp, Slack, Skype and their analogs is skyrocketing, Facebook Messenger alone has more than 1.2 billion monthly users. With the spread of messengers, virtual chatterbots that imitate human conversations for solving various tasks are becoming increasingly in demand. Chinese WeChat bots can already set medical appointments, call a taxi, send money to friends, check in for a flight and many many other.
Whilst the payout wasn't huge within the early days of Amazon, those who got in early are now seeing huge rewards, with 38% of shoppers starting their buying journey within Amazon (source), making it the number one retail search engine. Some studies are suggesting that Amazon is responsible for 80% of e-commerce growth for publicly traded web retailers (source).
In 2000 a chatbot built using this approach was in the news for passing the “Turing test”, built by John Denning and colleagues. It was built to emulate the replies of a 13 year old boy from Ukraine (broken English and all). I met with John in 2015 and he made no false pretenses about the internal workings of this automaton. It may have been “brute force” but it proved a point: parts of a conversation can be made to appear “natural” using a sufficiently large definition of patterns. It proved Alan Turing’s assertion, that this question of a machine fooling humans was “meaningless”.
Other companies explore ways they can use chatbots internally, for example for Customer Support, Human Resources, or even in Internet-of-Things (IoT) projects. Overstock, for one, has reportedly launched a chatbot named Mila to automate certain simple yet time-consuming processes when requesting for a sick leave.[24] Other large companies such as Lloyds Banking Group, Royal Bank of Scotland, Renault and Citroën are now using automated online assistants instead of call centres with humans to provide a first point of contact. A SaaS chatbot business ecosystem has been steadily growing since the F8 Conference when Zuckerberg unveiled that Messenger would allow chatbots into the app.[25]

It takes bold visionaries and risk-takers to build future technologies into realities. In the field of chatbots, there are many companies across the globe working on this mission. Our mega list of artificial intelligence, machine learning, natural language processing, and chatbot companies, covers the top companies and startups who are innovating in this space.
One of the first stepping stones to this future are AI-powered messaging solutions, or conversational bots. A conversational bot is a computer program that works automatically and is skilled in communicating through various digital media—including intelligent virtual agents, organizations' apps, organizations' websites, social platforms and messenger platforms. Users can interact with such bots, using voice or text, to access information, complete tasks or execute transactions. 
For designing a chatbot conversation, you can refer this blog — “How to design a conversation for chatbots.” Chatbot interactions are segmented into structured and unstructured interactions. As the name suggests, the structured type is more about the logical flow of information, including menus, choices, and forms into account. The unstructured conversation flow includes freestyle plain text. Conversations with family, colleagues, friends and other acquaintances fall into this segment. Developing scripts for these messages will follow suit. While developing the script for messages, it is important to keep the conversation topics close to the purpose served by the chatbot. For the designer, interpreting user answers is important to develop scripts for a conversational user interface. The designer also turns their attention to close-ended conversations that are easy to handle and open-ended conversations that allow customers to communicate naturally.
Some brands already seem to be getting the balance right. A bot needs to capture a user's attention quickly and display a healthy curiosity about their new acquaintance, but too much curiosity can easily push them into creepy territory and turn people off. They have to display more than a basic knowledge of human conversational patterns, but they can't claim to be an actual human -- again, let's keep things from getting too creepy here.

…utilizing chat, messaging, or other natural language interfaces (i.e. voice) to interact with people, brands, or services and bots that heretofore have had no real place in the bidirectional, asynchronous messaging context. The net result is that you and I will be talking to brands and companies over Facebook Messenger, WhatsApp, Telegram, Slack, and elsewhere before year’s end, and will find it normal.

Back in April, National Geographic launched a Facebook Messenger bot to promote their new show about the theoretical physicist's work and personal life. Developed by 360i, the charismatic Einstein bot reintroduced audiences to the scientific figure in a more intimate setting, inviting them to learn about the lesser-known aspects of his life through a friendly, natural conversation with the man himself.

The classic historic early chatbots are ELIZA (1966) and PARRY (1972).[10][11][12][13] More recent notable programs include A.L.I.C.E., Jabberwacky and D.U.D.E (Agence Nationale de la Recherche and CNRS 2006). While ELIZA and PARRY were used exclusively to simulate typed conversation, many chatbots now include functional features such as games and web searching abilities. In 1984, a book called The Policeman's Beard is Half Constructed was published, allegedly written by the chatbot Racter (though the program as released would not have been capable of doing so).[14]