This is the most frustrating aspect of things like Slack & HipChat.
I once had a business that did nearly everything in Campfire, but there were three of us.
At the moment, I’m on a large team and we have multiple HipChat rooms (broken out by sprint team, etc). The constant chatter and lack of social norms between each room make it a mess. It’s way to difficult to go back and find things that you miss.
On top of that there are three active Slack domains I’m in (each with a subset of their own channels).
Asynchronous channels for any train of though that is longer than 20 minutes is superior in my opinion. Async empowers the participant to act on their own terms, prioritizing all the incoming and outgoing work-streams in the individual context that makes sense to them. Always-on realtime channels disempower the message recipient because they create expectations that are unsustainable in the long run. They let others rob you of your ability to self-direct.