Invisibility is the name of the game when it comes to ghostwriting. It is universally accepted that a ghostwriter's name will never appear on the book cover, copyright page, book description, official listings or any place else.
The Regular Arrangement
When you sign up to be a ghostwriter, it predominantly means nameless invisibility is outright.
After the book has been published by said author, and listed on Amazon not a single word will be mentioned about the contribution the ghostwriter has made to the creation of the book.
Especially when an NDA (Non-Disclosure Agreement) has been signed, nobody will know that the ghostwriter has written that book.
That said, there is a way to get around that if the author is in agreement with the ghostwriter.
However, there is a simple workaround in the acknowledgements section that can be used whereby a small mention can be made. Which needs to be sufficiently indistinct that the readers won't work out who the real author is. You could say something like 'Help was given with the writing by ...'. This is a roundabout way of saying that you did help with the book, but you're not alluding to how much help was really given.
The audience will surmise that you only furnished the author with practical guidance and opinion. However, those in the publishing industry looking for new blood will see a ghostwriter with fresh talent and keen to work.
How Does It Work When You Co-Author a Book?
In this situation both the client and ghostwriter are named on the front cover as well as in the listings. It doesn't matter how much the ghostwriter has contributed to the work, the billing is still shared.
It also helps generate more exposure to the ghostwriter's own books, and any writing they might have online.
Having equal billing means you share in the praise and promotion of the book, and this can be on social media, to book signings. Books with more than one author often get more exposure on Amazon, so it's a win-win situation.
It's worth pointing out that the rights of the book still belong to the client and not the ghostwriter, so a little reassurance on the part of the ghostwriter won't go amiss when asking for co-authorship of the book.
The Celebrity Solution
Celebrities don't hesitate to tell the world about their entourages, gardeners, housemaids, nannies or cooks. So why would they be afraid to mention the fact they had a little help from a ghostwriter.
The best ghostwriters are sought after in the celebrity world when it comes to book writing. And many ghostwriters have become celebrities in their own right because of it.