I don't even get IRC or IM. "Chat" is noise and distraction. Write proper emails or arrange phone calls.
What exactly are people using slack for? I don't get it.
We need to discuss something visual as a five-person team? A phone conference is the wrong medium.
We need to collaborate on a significant technical document? Slack is the wrong medium.
We need to have a searchable back-and-forth discussion, interleaved with other things that are vying for our attention? We should probably use a chat tool.
This is email.
> We need to discuss something visual as a five-person team? A phone conference is the wrong medium.
Shared desktop conference, such as gotomeeting.
However, the growing number and popularity of alternatives should be a strong signal that they do not work for every team.