Yes, used right it does. A lot. Sure, you can use it for goofing off, too, so you should have some etiquette in place for which channels are kept serious, which

Yes, used right it does. A lot. Sure, you can use it for goofing off, too, so you should have some etiquette in place for which channels are kept serious, which aren't (and can safely have notifications turned off), which announcements warrants @channel or @here or @person and which don't. A company where people who feels that it's OK to put a notification on 2000 devices to say "Good morning" or "Lunch, anyone?" can't be reprimanded is a sick company, with or without Slack. It's important to keep in mind that these etiquettes are the same (or at least very analogues to) the ones that are required for email and especially email lists. A company where everybody puts everybody in the To: line of every email will feel that email is a destructive force, but one that cultivates decent distribution list culture and caution about CC'ing the world or replying to all will feel that it is much more useful.