What are some alternatives?
When comparing Botfuel and Dialogflow, you can also consider the following products
Conversational Form - Turning web forms into conversations. By SPACE10
Amazon Lex - Harness the power behind Amazon Alexa for your own conversational apps.
Chatfuel - Chatfuel is the best bot platform for creating an AI chatbot on Facebook.
IBM Watson Assistant - Watson Assistant is an AI assistant for business.
Botpress - Open-source platform to create, manage and extend bots