Another innovation introduced with this new format is the ability to rent ebooks rather than buying them. Books can typically be rented for between 30 to 360 days, although the exact limits will vary from book to book. And rented book can be bought with full credit given for the rental fee, if bought before then end of the rental period.

Had to happen really.

Also new in the latest Kindle software: fixed layout ebooks (like PDFs) for books with complex formatting.