Having an audiobook, ebook and physical book shows that you are a serious author. When we create and list your audiobook, we will add the audiobook to your Amazon listing, regardless if you published your physical book with us or not. When potential buyers look for book, your Amazon listing will show all available formats.
There are around 500,000 books on Audible while there are millions on Amazon. Having an audiobook makes you easier to find for those who prefer the audiobooks.