How can you grab a listeners attention?

By adding facts, fun facts, and eye contact.

Try your best to have, a clear unnervous voice have good eye contact, if your trying to convince him of something like, if you want him to read your book ask something like: "Have you ever walked stood right in front of a mummy?" If the listener says no then say: This book brings you deep in the history of Egypt and completely inserts you into the history of ancient Egypt, please take one for free and tell me what you think.

-Hope this helps, Nexxmexx :3