What are some alternatives?
When comparing Botfuel and Amazon Lex, you can also consider the following products
Conversational Form - Turning web forms into conversations. By SPACE10
IBM Watson Assistant - Watson Assistant is an AI assistant for business.
Tars - TARS enables users to create chatbots that replaces regular old webforms.
Dialogflow - Conversational UX Platform. (ex API.ai)
SentiOne - Insightful social listening and online reputation management platform.