[Samuel_Michon]

That’s true if you think tablets should only be used in landscape orientation. I like using the iPad in portrait mode, but on 16:9 screens portrait mode is very awkward for everything but reading novels.

As for smartphones: the maximum width of those screens is dictated by the average size of a human’s palm. If you make the screens wider than 2.5", for most people it will be uncomfortable to operate the phone with one hand. Look at the Galaxy Note[1] (which is 3.3" wide), it’s practically impossible to use with one hand.

[1] http://www.engadget.com/gallery/samsung-galaxy-note-ii-hands...

[jonas_maj]

For something you need to hold with both hands(which I assume how you use your iPad), I think the landscape orientation is more natural and comfortable. That's how we hold a book while reading lying down.

[Samuel_Michon]

The vast majority of books are taller than they are high. It’s way more natural to read books on the iPad in portrait orientation, and that’s also how it’s shown in iPad commercials[1].

[1] http://www.youtube.com/watch?v=bhC40QCZML0

[jonas_maj]

When you open a book (which is the only way you can read it!), it is definitely wider than it is tall. And hence I find it much more natural to hold a tablet in the landscape mode.

[Samuel_Michon]

Most books have pages that are taller than they are high, the text blocks on those pages are definitely taller than they are wide. Paragraphs don’t run in one line from the verso to the recto[1]. A ‘page’ is one side of a sheet, you don’t read two pages at the same time.

[1] https://en.wikipedia.org/wiki/Recto_and_verso