It's social proof that you're an expert. You'll often get work just by being at these places in the role of a speaker, if you're looking for it. There are many people who have clients they either don't like the work from the client, or want to get help with a thing -- so they can handoff clients/work to you.

We are talking about consulting right? You want to pitch technical topics to non-technical (owners presumably)?

Find a way to meet them and literally tell them that "you wrote the book on that (said subject that will... Fill in the blank)". Then hand them a copy of the book .

Folks like to work with experts (or people who are passionate enough to write a book).