[Refefer]

Clearly a chatroom with half a million individuals is unusable from pretty much every perspective. That said, a chat server with N chatrooms and a total population of 500k users sounds like a good day on IRC and well within the realm of what something like this could potentially handle.

[felixgallo]

That depends very much on what's doing the chatting. If it's code chatting with other code -- for example, mobile devices receiving near-real-time notifications -- then half a million is just getting started.

[nickpsecurity]

Exactly