The timing of the promotion suggests Apple is trying to help out people who are stuck inside during the coronavirus pandemic. This appears to be a limited-time offer, so if you're interested, take advantage as soon as you can.

Once you've finished reading your freebie from Apple Books, you can turn to an app like Libby to get more reading material. Libby allows you to borrow e-books and audiobooks from your local library. All you need is a library card, which, in most instances, you can get for free.