Ideograms and SMS

There is much evidence that SMSes are more used in the Far East then they are in other parts of the world. It's no surprise mobile is generally more widespread there, but somehow I cannot imagine reading a book on the screen of a mobile phone. Is it just lack of imagination - or perhaps the text in ideograms just takes less screen estate to convene the same meaning? I don't know. I've tried to look at some web pages (like www.un.org) in English and in Japanese or Chinese - frankly I don't see any difference - but there must be some. Does any one have some real data here?