There's no doubt that epub is the future of ebook standards. (arthurattwell.com)
Also, most ebook standards did not support manga, the nations most popular type of book. (goodereader.com)
If you're charging $ 9.99 (a high price by indie - published ebook standards), you've just lowered your royalty from 70 % to 40 %. (stillpointdigital.com)