You bring up a good question, Faker. Often times I have thought of me being on the chat too long or every day, etc. along with the idea of the reasonable time zones. However, there many people that are online at the same time but they may not yet see the chat at the bottom of the browser or they may not be bothered to chat. Nevertheless, I have met many from time to time that will noticed that chat and start up a conversation. There is another thread that is up about the chat, but I am not sure if it is the one that stays at the top which it should be if that is possible.
Note: The network chat does show the number of people online within the network; not just in the chat and it is at the bottom of the browser at the right. Just hoover over it until it turns gray and click on it. It will pop up and you can also have the option of having it pop out of the browser. The sound is on for notification of chat activity.
I checked it out when it was announced as a new feature, but since then, I haven't even opened it.
From what I understand, when you sign into 20SB, you are automatically signed into the chat room too. But most people don't even realize they are listed in the chat room because most people don't bother opening the chat window.
I'm not much of an online chatter myself (not interested and don't have the free time), but I do use AIM or Gchat sometimes with my friends.