Different people have different preferences, of course. If given the choice, I also flip by page. However, autoscroll is probably one of the easiest ways to read WITHOUT using your hands (think about holding yourself on a bus, etc). Also, there are different types of autoscrolls, some are linear, some have a movement pattern (my demo above uses something closer to a sinusoidal cycle), some even vary letter sizes in the process. It's really just about finding which is the most convenient way to flip pages given certain physical circumstances.