So a lot of times, on a project, maybe right after a production deploy, I'll just keep the production logs open on a spare monitor or a TV, and passively keep an eye on what's going on while working on other things. I'm not looking for anything specific: my intuition just kinda kicks in if something seems amiss. Suddenly jumped from a few errors a minute to a continual stream of backtraces? The logs stopped streaming entirely? I know it when I see it. Kinda like Cypher watching The Matrix.

Now, if I had to tab between panes across 2, 3, 6 app servers, background workers, and database instances, I just wouldn't bother. It's only useful as background noise. But that's fine, because there are tools that let me easily consolidate all of my logs into one stream.

And that's how I see Slack. Just like I can't get a notification every time I have one exception happen in production, because it would kill my workflow, I can't get a notification every time somebody updates a Trello card or resolves a Zendesk ticket. But what I /can/ do is passively watch the stream: Slack is the consolidated logfile, not for my production servers, but for my company.

Could I configure all that with IRC? Yes. Do I want to set it all up, when Slack lets me OAuth against every single service imaginable with one click? No, I really don't. My time is far more productively spent elsewhere.

Search is also a major feature.

For integrations, Github tells us when there's a PR. Yes, there's a clickable hyperlink, but I also get to know a bit more inline. It's additional context you don't get with only a hyperlink. There's less switching contexts when things are inlined ... it's a UX feature. I'd call it a feed of things happening across all of my apps, mixed with the ability to discuss those things in a standard place.

The integrations also give you shortcuts to actions without switching from your "command" line. Sure there are _some_ tools you can install on your local machine, but none make it this easy. Butterfield had the same success with Flickr (which yahoo subsequently destroyed) in making a killer user experience. That was for photos, Slack is for communication.

I'd say slack/hipchat has become the repository of alerts/notifications/etc that I would normally receive through e-mail. A lot of times these notifications aren't super mission critical and don't require immediate attention, but it's nice to have the history of them so I can investigate when necessary.

Having this outside of e-mail keeps my e-mail inbox less cluttered. That's my reason anyways.

I can't speak for the rest, but I personally use the GitHub integration to be notified in chat when builds have failed, pull requests are submitted and commented on, etc. Otherwise I end up having to keep GitHub open in a tab and refresh every minute.

I prefer having everything in one place possible. Clicking a link means a new tab, and if you have multiple systems, that's a new tab for each system and its links. Gets out of hand quickly.