I have searched for this older article on the forum but haven't find -
http://toc.oreilly.com/2013/02/the-p...-solution.html
Whenever someone proposes EPUB as a solution, ask yourself a question: what’s the problem they’re trying to solve? As a standard drafted by the IDPF, a self-proclaimed “organization for the Digital Publishing Industry”, EPUB is built squarely to address the industry’s biggest headache: ensuring that, in the digital age, they retain the ability to charge money for distributing content. The best interests of authors or readers simply do not figure in the equation.
Your take? I don't know is EPUB (besides being version 2 or 3) a good format in itself or you could come up with a better proposition?