What I mean is not used in any of my projects or work. I have accessed it when working on Elm, and after loading it once cannot even understand why Elm a language which wants 0 runtime error in JavaScript can even accept such a slow system. Even if Elm wanted wanted a web user interface on top of IRC, they could have gone with discord app (although personally I still prefer IRC), which is far far ahead of slack when it comes to quality, latency and works much faster.

But doesn't matter in a hurry to replace e-mail with something different companies are choosing much worse solution like Slack. Email, IRC are very good. Slack is a product of spending millions on advertising and marketing and be loss making for as long as possible and than list it to let it gamble on stock exchange or get acquired by bigger company.

  +---------+--------+---------+---------+---------+
  |         |ttm     |1/30/2019|1/30/2018|1/30/2017|
  +---------+--------+---------+---------+---------+
  |Operating|-540,530|-154,208 |-143,851 |-148,503 |
  |Income or|        |         |         |         |
  |Loss     |        |         |         |         |
  +---------+--------+---------+---------+---------+