One of the most common questions people have with e-readers and e-books is the exact number of pages are inconsistent with the print edition. This is primarily due to the fact that e-books don’t have “pages” in the usual sense. Anytime you see a mention of e-book pagecount, it’s an abstraction. Sort of like if I told you something was an hour’s walk away.
The “page count” on e-readers is based on an arbitrary metric and may vary across platforms. It is not set by the publisher, so it will differ from the print edition.
Page counts and line-spacing are basically non-standardized. Some e-Book platforms may count 250 consecutive words as a “page”, while others may use a different metric. Some also exclude front and back matter, dedications, acknowledgments, author bios, and other non-relevant content. No one actually knows what any single metric is, but there are some approximations being thrown around.
The big problem with e-book page numbers being different than printed books is due to software that packages EPUBS. Adobe has a different system for anyone using their Digital Publishing solution than a big publisher that uses in-house tools based on best practices by the IDPF. The other problem is that companies like B&N and Kobo have different way to show progress in a book. Sometimes they will show you how many hours are remaining and in other cases page numbers are based on the chapter you are reading.