Vice has a great piece on the evolution of bots -- from social bots, news bots, entertainment bots and a look at some deeper questions on policy and regulation of semi-autonomous bots.
While this has got more to do with actual "voices", it is interesting to note that bot creators also have to deal with giving their bots a "personality" and how writers are as important as developers themselves for sculpting a bot's persona.
Rohin Dhar of Priceonomics talks us through his experience with launching Content Tracker on the Slack App Store. While there isn't a silver bullet that solves distribution and engagement challenges for SaaS startups, the Slack App Store has definitely been an accelerator for Content Tracker.
Clement Vouillon of Point Nine Capital raises some very pertinent questions about chat bots. Like any other business or product out there, we need to look at whether chat bots are a new product category or a feature of a messaging platform.