The interesting audiobook will transform casual listeners into readers. When your audio version is made right, with good narration, right tone, and normal rhythm, you are not just providing content, you are providing experience.
People who love great audiobooks tend to buy the print or ebook versions, subscribe to social media, and tell others about the experience. Uniformity in formats creates trust and your identity as an author. When your audiobook sounds professional and emotional, then it will create an impression that will stay with the readers, as they will go back to listen to more.