Infinite scrolling websites are great for browsing images, but there’s no easy way to mark your place in the lengthy stream of information – lose your spot, and you’re doomed to spend the next hour scrolling back to something you spot thirty minutes ago. Of course, it’s perfect for browsing unlimited cat videos on your phone, but it’s no way to read a book.

This comic from xkcd illustrates why some things, like page numbers, are great, no matter what kind of medium you’re using.