A great way to generate income is by writing eBooks and recording audiobooks, then selling them through Simplero. With audiobooks, customers can easily listen via the built-in player or on the web. However, this convenience doesn’t extend to eBooks, as Simplero does not support the ePub format. So why don’t I simply sell digital books as downloadable files? The main reason is the lack of copyright protection for the files. That said, since ePub is essentially a compacted HTML + CSS file, I believe implementing an eBook reader in Simplero would be a relatively straightforward feature to develop.