Why do you need an InDesign file to create my eBook? What's wrong with a PDF?

Pdf files are essentially written in stone and are extremely difficult to modify. There's no easy way of converting a pdf to an ePub unless you convert it to an image. This, however, eliminates the possibility of enlarge fonts since you would now have an image. We need to create an InDesign file in order to use the cascading style sheets that will give your ebook the proper look.