The chatbot uses keywords that users type in the chat line and guesses what they may be looking for. For example, if you own a restaurant that has vegan options on the menu, you might program the word “vegan” into the bot. Then when users type in that word, the return message will include vegan options from the menu or point out the menu section that features these dishes.
Want to initiate the conversation with customers from your Facebook page rather than wait for them to come to you? Facebook lets you do that. You can load email addresses and phone numbers from your subscriber list into custom Facebook audiences. To discourage spam, Facebook charges a fee to use this service. You can then send a message directly from your page to the audience you created.
If AI struggles with fourth-grade science question answering, should AI be expected to hold an adult-level, open-ended chit-chat about politics, entertainment, and weather? It is thus encouraging to see that Microsoft’s Satya Nadella did not give up on Tay after its debacle, and Amazon’s Jeff Bezos is sponsoring an Alexa social chatbot competition. I love this below quote from Jeff:

In 1950, Alan Turing's famous article "Computing Machinery and Intelligence" was published,[7] 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: