Depending on the nature of the chats, around a half dozen is my limit. If you've got 1-2 that are only responding to you every 10 minutes or so, or 1-2 have easy general questions, that number could probably push higher. But around 5 conversations that require legitimate investigation and troubleshooting is where I've found you can start to lose engagement.
bcx|13 years ago
Where number of messages per minute is my real limit. (unless I am trying to trouble shoot a bunch of issues at the same time)