Here are some ideas:
1) Create a Facebook event
Invite all of your friends to the event and make the event open so that they can invite their friends
2) Send out an email to your current client bases giving them a special discount to come. Maybe even give it to them for free if they bring a friend or two.
3) Work closely with the Hotel
They might be willing to do one or all of the following:
– Put a flyer out somewhere in the hotel (front desk, concierge, gym, in room binder, etc)
– Include your retreat as an upcoming event in their emails to past guests and leads
– Include your retreat on the in room hotel TV channel (the channel that always comes on when your turn on your TV and is talking about the hotel)
– List your event on their website and social media posts (FB and Twitter)
4) Write a blog post
Write a blog post with the title “Malibu Pilates Retreat”. Explain/pitch the event and include a link for where someone can go sign up. I noticed that there isn’t much competition for the keywords “Malibu Pilates Retreat” on google so your post should show up relatively high once indexed.
I hope this helps, I will post more ideas if I think of any. Good Luck!