Chat is kind of difficult to make succeed in terms of people actually going to the chat. It works if you have a good scheduling system like the MS one where you get outlook to remind about the chat by pushing the .ics files. If you don't have scheduled chats then you need to think about having indicator about participants in the chat outside the chat room. And if it always shows 0, it begs one to ask why go to chat if no one is there. If you can have someone always there atleast during working hours I guess that resolves that problem nicely if you use the indicator. If you have an actual IRC channel behind the web chat, you can have a irc bot (to remind visitors about when you have people there or whatever) and possibly few people there. For the web interface there doesn't have to be much indication that it's actually an IRC based chat.