“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
The term chat bot (or sometimes just bot) can also be used in the meaning of an automatic chat responder program. The article How to Create a Chat Bot for Yahoo Messenger written by Chelsea Hoffman, explains how quick and easy it is to create a Chat bot responder containing unique and accurate responses to general phrases, words and questions that are used in Yahoo messenger.
Respect the conversational UI. The full interaction should take place natively within the app. The goal is to recognize the user's intent and provide the right content with minimum user input. Every question asked should bring the user closer to the answer they want. If you need so much information that you're playing a game of 20 Questions, then switch to a form and deliver the content another way.
Since 2016 when Facebook allows businesses to deliver automated customer support, e-commerce guidance, content and interactive experiences through chatbots, a large variety of chatbots for Facebook Messenger platform were developed. In 2016, Russia-based Tochka Bank launched the world's first Facebook bot for a range of financial services, in particularly including a possibility of making payments.  In July 2016, Barclays Africa also launched a Facebook chatbot, making it the first bank to do so in Africa. 
Chatting with a bot should be like talking to a human that knows everything. If you're using a bot to change an airline reservation, the bot should know if you have an unused credit on your account and whether you typically pick the aisle or window seat. Artificial intelligence will continue to radically shape this front, but a bot should connect with your current systems so a shared contact record can drive personalization.