How is the eBook fulfillment process impacted by 13-digit ISBNs?
Historically, the assignment of an ISBN to each eBook format has been handled differently by the publishing community. Some publishers assign an ISBN to each eBook format; other publishers assign a single ISBN at the eBook level (a single ISBN for all formats); and still other publishers do not assign a separate ISBN at all for an eBook, preferring instead to reference the eBook by its print ISBN counterpart. Because of this diversity in ISBN assignment, LSI has always assigned its own distinct identifier known as a SKU. This is a 10-digit identifier with a check-digit structure mimicking an ISBN, but which is not a registered ISBN. Every distinct format of every eBook is assigned a distinct SKU.
