Slack grew compared to IRC. That showed the world what people want out of real-time messaging. Email grew relative to walled-garden solutions. That only shows w

Slack grew compared to IRC. That showed the world what people want out of real-time messaging. Email grew relative to walled-garden solutions. That only shows what people want out of asynchronous messaging. My conclusion to all this is that people tend to use synchronous messaging in teams, and asynchronous messaging for everything else. Interconnectivity is more important for asynchronous messaging. Ease of use is more important for synchronous messaging. Email could never have been unseated by any of it's would-be competitors, whereas IRC was always bound to get usurped. It could never have kept up with the needs of the market. Now synchronous messaging is moving in the direction that web browsers started moving 15 years ago. The killer app has been found, now entrants are going to compete on ideology, while the standards people try to balance the profit motive with the need for interoperability. edit: missing is SMS, which occupies a weird middle ground between synchronous and asynchronous messaging. But its openness is more akin to email than Slack.