Mild curiosity has me whipping out my handy dandy Martha Stewart Crafts ruler.
Looking at a kepub, the width of the title bar is 1/2 inch, appears to be the same space as when accessing the menu from inside a book.
Looking at an epub with font, line spacing, and margins reduced to nil, the blank space at the top is 1/8 of an inch.
A difference of 3/8 of an inch. Within that 3/8 space at the nil settings you could almost get 3 lines of text.
3/8 of an inch hasn't caused this much excitement since the 6th grade.
