ManyChat helps you create Facebook Messenger bot easily for marketing, sales, and support. Their visual drag and drop bot builder helps you set up Facebook Messenger bot in a very short time. It provides you a set of tools to help you grow your Messenger audience. And it helps you broadcast your message effectively with Messenger. You can also automate your Messenger marketing.
This form of obtaining information from the collective intelligence of a large number of people allows Cleverbot to respond in new conversations by taking into account the context of the conversation typed by a user and searching its database for an appropriate response. It scans its history for every user-submitted response to the given question and replies accordingly, which creates a more human-like conversation with users.
Fortunately, the next advancement in chatbot technology that can solve this problem is gaining steam -- AI-powered chatbots. By leveraging machine learning and natural language processing, AI-powered chatbots can understand the intent behind your customers’ requests, account for each customer’s entire conversation history when it interacts with them, and respond to their questions in a natural, human way.

Cons: Botengine has reduced the workload on the helpdesk department . However ,I fear we may come one day have an advanced Botengine ,years down the line ; which is able to respond to the current complex queries we respond to and thus when that day comes , why would my employer keep me at the job ,when a Bot can do a better job ,without ever getting tired?