Paul Johnson has put together a robust call to action in his blog post about Drupal Business Day at http://bit.ly/UlLteN which makes for entertaining and informative reading.
The basic gist is we need to sell a minimum 15 more tickets by this Friday January 16 for the day to go ahead, so there's no time to waste getting the word out about it. Paul's post has a load of tips about how you can help so DrupalCon Sydney is really about "Growing Drupal Downunder" to a new base of users.
At only $195, Drupal Business Day is amazing value for a fully catered day of interesting case studies and Drupal experts sharing their experiences.
Don't delay if you're thinking of attending, and grab your tickets now at http://sydney2013.drupal.org/register/drupal-business-day