on Kindlepreneur:
You might not think that file formats matter when it comes to your eBook.
But you would be sadly mistaken. It might not matter to you, but it does to Amazon and other eBook publishers.
That’s why it’s so important to make sure you have properly converted your EPUBs to MOBI and vice versa. Here’s an example:
Let’s just say you purchased an eBook off of Apple Books. Now, there’s a good chance that it came formatted as an EPUB file. You try to open it up on your Kindle but to no avail. This is because your Kindle (an Amazon product) needs a MOBI file. It’s like trying to fit a round peg into a square hole.
So, the real question is…
Chris The Story Reading Ape's Blog 