|From: The School of Library, Archival and Information Studies, UBC|
"[...] And unlike musicians, authors are not commonly charged for production expenses.
A recording contract typically requires musicians to sell enough to pay for all the production, publicity, and marketing before they see a penny in royalties. In publishing, the publisher pays these expenses out of its pocket, and the author isn’t expected to pay it back.
Finally, authors’ advances are (usually) only charged to their current books, or sometimes across a single deal. Unlike musicians, who are often required to pay back shortfalls from their last project before they can start earning on their latest one, authors’ balance sheets are zeroed out with each new book. If your last book tanks, your next book usually doesn’t have to pay back its advance. Publishing doesn’t do debt slavery."
— Cory Doctorow, Publishers Weekly