One key reason: The technology that powers bots, artificial intelligence software, is improving dramatically, thanks to heightened interest from key Silicon Valley powers like Facebook and Google. That AI enables computers to process language — and actually converse with humans — in ways they never could before. It came about from unprecedented advancements in software (Google’s Go-beating program, for example) and hardware capabilities.
Chatfuel is a platform that lets you build your own Chatbot for Messenger (and Telegram) for free. The only limit is if you pass more than 100,000 conversations per month, but for most businesses that won't be an issue. No understanding of code is required and it has a simple drag-and-drop interface. Think Wix/Squarespace for bots (side note: I have zero affiliation with Chatfuel).

Chatbots such as ELIZA and PARRY were early attempts at creating programs that could at least temporarily fool a real human being into thinking they were having a conversation with another person. PARRY's effectiveness was benchmarked in the early 1970s using a version of a Turing test; testers only made the correct identification of human vs. chatbot at a level consistent with making a random guess.
This is the big one. We worked with one particular large publisher (can’t name names unfortunately, but hundreds of thousands of users) in two phases. We initially released a test phase that was sort of a “catch all”. Anyone could message a broad keyword to their bot and start a campaign. Although we had a huge number of users come in, engagement was relatively average (87% open rate and 27.05% click-through rate average over the course of the test). Drop off here was fairly high, about 3.14% of users had unsubscribed by the end of the test.
To envision the future of chatbots/virtual assistants, we need to take a quick trip down memory lane. Remember Clippy? Love him or hate him, he’s ingrained in our memory as the little assistant who couldn’t (sorry, Clippy.).  But someday, this paper clip could be the chosen one. Imagine with me if you will a support agent speaking with a customer over the phone, or even chat support. Clippy could be listening in, reviewing the questions the customer is posing, and proactively providing relevant content to the support agent. Instead of digging around from system to system, good ‘ole Clippy would have their back, saving them the trouble of hunting down relevant information needed for the task at hand.

Two trends — the exploding popularity of mobile messaging apps and advances in artificial intelligence — are coinciding to enable a new generation of tools that enable brands to communicate with customers in powerful new ways at reduced cost. Retailers and technology firms are experimenting with chatbots, powered by a combination of machine learning, natural language processing, and live operators, to provide customer service, sales support, and other commerce-related functions.
Despite the fact that ALICE relies on such an old codebase, the bot offers users a remarkably accurate conversational experience. Of course, no bot is perfect, especially one that’s old enough to legally drink in the U.S. if only it had a physical form. ALICE, like many contemporary bots, struggles with the nuances of some questions and returns a mixture of inadvertently postmodern answers and statements that suggest ALICE has greater self-awareness for which we might give the agent credit.

A chatbot (sometimes referred to as a chatterbot) is programming that simulates the conversation or "chatter" of a human being through text or voice interactions. Chatbot virtual assistants are increasingly being used to handle simple, look-up tasks in both business-to-consumer (B2C) and business-to-business (B2B) environments. The addition of chatbot assistants not only reduces overhead costs by making better use of support staff time, it also allows companies to provide a level of customer service during hours when live agents aren't available.
The educators or class organizers can opt for chatbots to simplify daily routine tasks. Chatbots may serve as a helping hand to the teacher in dealing with the daily queries by allowing bots to answer the questions of students on a daily basis, or perhaps even check their homework. Eventually, they offer teachers more time to work with their students on a one-by-one basis.

Bots are also used to buy up good seats for concerts, particularly by ticket brokers who resell the tickets.[12] Bots are employed against entertainment event-ticketing sites. The bots are used by ticket brokers to unfairly obtain the best seats for themselves while depriving the general public of also having a chance to obtain the good seats. The bot runs through the purchase process and obtains better seats by pulling as many seats back as it can.

It’s not all doom and gloom for chatbots. Chatbots are a stopgap until virtual assistants are able to tackle all of our questions and concerns, regardless of the site or platform. Virtual assistants will eventually connect to everything in your digital life, from websites to IoT-enabled devices. Rather than going through different websites and speaking to various different chatbots, the virtual assistant will be the platform for finding the answers you need. If these assistants are doing such a good job, why would you even bother to use a branded chatbot? Realistically this won’t take place for sometime, due to the fragmentation of the marketplace.

Chatbots can have varying levels of complexity and can be stateless or stateful. A stateless chatbot approaches each conversation as if it was interacting with a new user. In contrast, a stateful chatbot is able to review past interactions and frame new responses in context. Adding a chatbot to a company's service or sales department requires low or no coding; today, a number of chatbot service providers that allow developers to build conversational user interfaces for third-party business applications.

We need to know the specific intents in the request (we will call them as entities), for eg — the answers to the questions like when?, where?, how many? etc., that correspond to extracting the information from the user request about datetime, location, number respectively. Here datetime, location, number are the entities. Quoting the above weather example, the entities can be ‘datetime’ (user provided information) and location(note — location need not be an explicit input provided by the user and will be determined from the user location as default, if nothing is specified).

NBC Politics Bot allowed users to engage with the conversational agent via Facebook to identify breaking news topics that would be of interest to the network’s various audience demographics. After beginning the initial interaction, the bot provided users with customized news results (prioritizing video content, a move that undoubtedly made Facebook happy) based on their preferences.
Consider why someone would turn to a bot in the first place. According to an upcoming HubSpot research report, of the 71% of people willing to use messaging apps to get customer assistance, many do it because they want their problem solved, fast. And if you've ever used (or possibly profaned) Siri, you know there's a much lower tolerance for machines to make mistakes.
There was a time when even some of the most prominent minds believed that a machine could not be as intelligent as humans but in 1991, the start of the Loebner Prize competitions began to prove otherwise. The competition awards the best performing chatbot that convinces the judges that it is some form of intelligence. But despite the tremendous development of chatbots and their ability to execute intelligent behavior not displayed by humans, chatbots still do not have the accuracy to understand the context of questions in every situation each time.
SEO has far less to do with content and words than people think. Google ranks sites based on the experience people have with brands. If a bot can enhance that experience in such a way that people are more enthusiastic about a site – they share it, return to it, talk about it, and spend more time there, it will affect positively how the site appears in Google.

Today, consumers are more aware of technology than ever. While some marketers may be worried about overusing automation and chat tools because their tech-savvy audience might notice. Others are embracing the bots and using them to improve the user journey by providing a more personalized experience. Ironically, sometimes bots are the key to adding a human touch to your marketing communications.

There are different approaches and tools that you can use to develop a chatbot. Depending on the use case you want to address, some chatbot technologies are more appropriate than others. In order to achieve the desired results, the combination of different AI forms such as natural language processing, machine learning and semantic understanding may be the best option.
This is a lot less complicated than it appears. Given a set of sentences, each belonging to a class, and a new input sentence, we can count the occurrence of each word in each class, account for its commonality and assign each class a score. Factoring for commonality is important: matching the word “it” is considerably less meaningful than a match for the word “cheese”. The class with the highest score is the one most likely to belong to the input sentence. This is a slight oversimplification as words need to be reduced to their stems, but you get the basic idea.
How: this is a relatively simple flow to manage, and it could be one part of a much larger bot if you prefer. All you'll need to do is set up the initial flow within Chatfuel to ask the user if they'd like to subscribe to receive content, and if so, how frequently they would like to be updated. Then you can store their answer as a variable that you use for automation.
Operator calls itself a “request network” aiming to “unlock the 90% of commerce that’s not on the internet.” The Operator app, developed by Uber co-founder Garrett Camp, connects you with a network of “operators” who act like concierges who can execute any shopping-related request. You can order concert tickets, get gift ideas, or even get interior design recommendations for new furniture. Operator seems to be positioning itself towards “high consideration” purchases, bigger ticket purchases requiring more research and expertise, where its operators can add significant value to a transaction.

Like apps and websites, bots have a UI, but it is made up of dialogs, rather than screens. Dialogs help preserve your place within a conversation, prompt users when needed, and execute input validation. They are useful for managing multi-turn conversations and simple "forms-based" collections of information to accomplish activities such as booking a flight.

Chatbots can direct customers to a live agent if the AI can’t settle the matter. This lets human agents focus their efforts on the heavy lifting. AI chatbots also increase employee productivity. Globe Telecom automated their customer service via Messenger and saw impressive results. The company increased employee productivity by 3.5 times. And their customer satisfaction increased by 22 percent.

What began as a televised ad campaign eventually became a fully interactive chatbot developed for PG Tips’ parent company, Unilever (which also happens to own an alarming number of the most commonly known household brands) by London-based agency Ubisend, which specializes in developing bespoke chatbot applications for brands. The aim of the bot was to not only raise brand awareness for PG Tips tea, but also to raise funds for Red Nose Day through the 1 Million Laughs campaign.

This machine learning algorithm, known as neural networks, consists of different layers for analyzing and learning data. Inspired by the human brain, each layer is consists of its own artificial neurons that are interconnected and responsive to one another. Each connection is weighted by previous learning patterns or events and with each input of data, more "learning" takes place.
“HubSpot's GrowthBot is an all-in-one chatbot which helps marketers and sales people be more productive by providing access to relevant data and services using a conversational interface. With GrowthBot, marketers can get help creating content, researching competitors, and monitoring their analytics. Through Amazon Lex, we're adding sophisticated natural language processing capabilities that helps GrowthBot provide a more intuitive UI for our users. Amazon Lex lets us take advantage of advanced AI and machine learning without having to code the algorithms ourselves.”

To inspire the next generation of explorers, NASA reaches out to students in schools, community organizations, and public events. A star robotic ambassador is “Rov-E,” a close replica of real NASA Mars rovers. Through Amazon Lex, NASA staff can now easily navigate Rov-E via voice commands -- an effective conversational interface when speaking with large crowds. Multi-turn dialog management capability enables Rov-E "to talk,” answering students’ questions about Mars in an engaging way. Integration with AWS services allows Rov-E to connect and scale with various data sources to retrieve NASA’s Mars exploration information. 
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.
Tay, an AI chatbot that learns from previous interaction, caused major controversy due to it being targeted by internet trolls on Twitter. The bot was exploited, and after 16 hours began to send extremely offensive Tweets to users. This suggests that although the bot learnt effectively from experience, adequate protection was not put in place to prevent misuse.[56]