Are you sure you didn't forget anything in the Advent Calendar?
To be sure, here is a checklist of what should be in place when the calendar goes live on December 1st.
Don't forget about Facebook
To get a lot of contestants you should activate the pre-sign up. This builds up expectations to the calendar goes live, and you can count down the days to Christmas with your customers. Post the link for the pre-sign up on Facebook and your web page, and wait for people to sign up. You will find this link by clicking Publish.
When the calendar goes live you should send an email reminder to the participants who pre-signed up. Go to Settings > Email reminder in the Advent Calendar to enter a reminder to the contestants, then choose which version of the calendar you want to link to.
To make it as efficient as possible, you should encourage the participants to like and share the advent calendar, and give an extra prize to the participants who recruit the most. Go to Participants > Referrals to see who recruited the most people.
If you decide to do this, remember to inform about the increasing chances of winning.
Good luck with this year's calendar!