Im also of the opinion that having a dedicated space for more "real time" communications can be really helpful as well. Team branded support room, for example. Having a space that everyone at least casually keeps an eye on can really save everyone a lot of time (especially when operating remotely) if a team member comes across an issue.
So, we have off-topic channels, a channel to plan social events (I Live in Austin Texas and we have more than one musician who will post events, and we've made company outings out of going to see a coworker perform), there's one for movie chats, and even a "LFG" (Looking for games) channel for the folks who like to play and discuss video games.
They're all as active and vibrant as our #devops and #product-discussions channels.
My team has "General" for company wide announcements and "random" for dumping gifs and whatnot.
There's also stuff like #sysadmin if something goes down or you spot a security bulletin and want to make sure the admin team sees it. Keep those rooms going as necessary. Low traffic, but the right people want an unread marker on them.
What drove us was a cultural shift away from immediate responses to task based responses. If you do stay with slack it seems like shifting that culture is the most thing to focus on.
I run a fully remote startup. My goal is to make as much communication asynchronous as possible, to facilitate people being in multiple time zones and having different optimal work times and places.
We have slack right now, but for the most part people understand that it's an async tool -- i.e. don't expect an instant response. Usually the only "instant" convo is if we're having a video meeting and need to share links (which of course we try to avoid since video meetings aren't async but are sadly unavoidable).
My question is, as we grow, how to I keep Slack that way, and make sure it doesn't turn into a huge distraction and just a bunch of gifs and watercooler talk, without imposing rules about "the proper use of Slack"?