I had a core group of people (~30) on a launch team who committed to attending and invited others. When the event went live (about 2 weeks before the party) they spread the word very effectively and we ended up having 4,000 people invited. 316 attended.
I’d previously attended about four FB parties and took a lot of notes on what I liked, didn’t like, etc. I then pre-planned the party, down to what I would post at what time, what I’d be giving away, videos I’d be sharing, etc. I posted every 10 minutes.
Posts included 5 giveaways, three 2-minute long video interviews, Q&A for the audience, small scene clips from the book, a few blog posts, and then some fun random pictures of snacks or Pinterest inspiration. (I can give a much more detailed list of things to include in posts if you need it.)
I announced the FB party via blog, social media, and newsletter one week prior, one day prior, and then the day of.
On the day of the party, I had another person (hubby) come in to help with behind-the-scenes. He was in charge of taking down names and drawing winners for prizes. My job was to interact with the attendees and to post the main pictures and giveaways.
The party ran for two hours (though, in hindsight, I think it should have been longer. Maybe 3 or 4.)