there is another option to get people into the chat room, which works better.
goto YOUR ACCOUNT, then scroll down till you see BROADCAST PUBLIC MESSAGE. just fill in that little area and click SEND. then along the top of the site for 10 minutes it will display your message. people only see the message once, but it will show people for 10 minutes.
this way people don´t have to look in the forum, they can just be browsing the site and notice the red bar along the top.