Either way, you're absolutely going to want the peace of mind knowing that those bits of private information in your Slack messages are going to remain private. That might mean work files that contain proprietary information, or it might mean office gossip that gets spread through direct messages.
But any platform that you do your work on is going to be tasked with handling some sensitive information. One part chat app, one part 'email killer' and business organization tool, the communication platform is an invaluable tool that lets you easily keep in touch with every member of your team.
Slack has become the de facto water cooler for thousands of companies, especially in the startup world.