Right now the younger uses don't predominate as one might guess.
http://jem499.blogspot.com/2012/08/t...ographics.html
The demographics cut so many different ways I am glad I don't have to decide what to release for hardware.
The academics want to lock epubs into standard book designs while the students want to customize everything!
Seems like no matter how you try to make it useable for everyone, you are bound to leave someone out in the cold.