Congrats on building up so many followers! The good news is: you already have a leg up since, by following you in the first place, these folks have expressed interest in what you're posting, and it sounds like your mini-book will tie in nicely with that content. Here are a few recommendations:

- Always Provide Value: When you begin promoting your book (and asking for money), stay extremely focused on providing value in EVERY way and every time that you communicate with your audience. This means tailoring the messaging around buying your book to show as much value as possible to THEM, and it also means continuing to post free, valuable, enjoyable content alongside your book promotions.

- Build Other Assets: Aggregate the most popular content you've shared on social media and put it elsewhere. Build a slideshare deck, start a blog, put together some sort of other offer, like a calendar with a daily inspirational quote. Then use these other assets to promote your book (at the end of the slideshare or blog post, or in an email nurturing series following a download of your offer).

- Design for Social Sharing: Let's not forget your big following is on social media right now. Keep growing that audience, and use that audience to do so! If these folks love your content, there's no harm in asking or encouraging them to share it. And make sure to include social share buttons on the landing page for your book, so people can spread the word about that too.

Hope this helps! If you want to hop on a call, I'd be happy to share more ideas.