The Slack DM you should have sent to channel
Slack DMs feel intimate and efficient. They're also where institutional knowledge goes to die. Most of them belong in a channel.
Someone DMs you a question. You answer it in the DM. Two days later, three other people ask the same question. Each gets a separate DM thread. Six months later, the same question has been answered eleven times, and the answer lives nowhere searchable.
The cost of DMs
Every DM is private knowledge. None of it is searchable by the people who'd benefit from it. Multiply that across an org and you've built a culture that quietly punishes new hires — they can't find anything because nothing is in a channel.
The fix
If a question could plausibly be asked by anyone else, the answer belongs in a channel. The person who asked might be embarrassed; the next eight people are quietly grateful. Norm this enough and your team's institutional knowledge becomes searchable.
DMs feel polite. Channels are the gift to everyone who'll ask the same question later.