"Good, complete information that's up-to-date will make your books discoverable. Simply put, if people can't find your books, they can't buy them. Rich information makes your books more visible, both to search engines and to readers, and every piece of information you can provide about one of your books is a chance to convert initial discovery and interest into a sale. All of the information that describes a book, from the title to the author photo to the fact that it won a literary award, is known as metadata. And good metadata is now the foundation of book marketing."

Increase Sales & Lower Costs With Better Metadata
A Step-By-Step ONIX Guide for Publishers