I use it everyday and it helps a lot when you connect it to various services (github, trello etc.) It offers dozens of them: https://slack.com/integrations
Ditto this, the integrations are really the icing on the cake for Slack.
We've even written notifications from our own applications to push into Slack, so we get notified on everything from continuous integration test results and deployments through to analytics and sales figures.
We've even written notifications from our own applications to push into Slack, so we get notified on everything from continuous integration test results and deployments through to analytics and sales figures.