I used to think the same but with IM, you have to find out the right account and add it (someone might prefer their personal gmail over corporate or whatever) ... but with this, everything is right there. completely replaced any need for im for me.
I don't understand- that only seems to hold if everyone agrees to use Slack.
If everyone agrees to use a single chat service, like OC (like most large enterprises), then you don't have to search anything but the company directory, so the comparison doesn't seem to make sense. What you're saying is that IM is sub-optimal because everyone uses different services, but Slack is better because everyone is forced to use it?
