Not sure what the author is talking about. I've been purchasing epub books exclusively since 2014. It's the format that unlocked me to start reading books on de

Not sure what the author is talking about. I've been purchasing epub books exclusively since 2014. It's the format that unlocked me to start reading books on devices. Prior to using epub format, I've tried on numerous occasions to read on devices but I couldn't make the jump. I use my 2018 ipad exclusively for reading. The only apps installed are apple books and safari.