A lot of companies gravitate towards putting more and more into Slack. It has a tendency to take over email. The integrations also just accelerate that process.
If you can convince people to put everything in "project rooms" (or "team rooms" or whatever) instead of DMs, then you effectively end up with the ability to search all the historical knowledge of the company.
If you can convince people to put everything in "project rooms" (or "team rooms" or whatever) instead of DMs, then you effectively end up with the ability to search all the historical knowledge of the company.