One problem that they failed to address in the Slack over IRC section is a damn near non-existent barrier to entry. I've introduced people and small teams to IR

One problem that they failed to address in the Slack over IRC section is a damn near non-existent barrier to entry. I've introduced people and small teams to IRC. I've also introduced people to Slack. IRC is just different enough, even when introduced to a team of technologists who grew on AIM and the like. Consider the onboarding experience - I emailed someone a link to a Slack channel, and before I heard back from them they'd signed up on my account and, unsolicitedly, downloaded the mobile client and were chatting with me. My setup time was nil, and there was no training. Sure, they could have downloaded Colloquy to their Mac and iPhone, and entered the settings, and hoped for the best, but I'm almost positive it wouldn't have gone so smoothly. That doesn't even include time to configure a bouncer for persistence. It's just anecdata, sure, but it counts for something, and helps to explain Slack's explosive growth.