Slack kicks email out of the park!

Our entire company uses Slack - every single department, and especially the people and sales reps who work remote. It completely takes away the need for email, and as a growing startup our inboxes are already cluttered as can be, so this helps to take out some of the needless emails that can take up space.
We use Slack for a variety of ways, from "general" channel, to joke channels, and department channels as well. We also use it for our morning conference calls, so people are able to speak and 'interrupt' with questions and comments in the Slack channel while not disrupting the conversation on the phone.