I have to agree with the space argument here. I live at my parents in an 8 foot square room. Space is precious to me, so much so that when buying something new I have to consider the possibility of getting rid of something old.
Buying digital games means I don't need more space and I don't have to sell old ones to make room. Win win.
Buying digital games means I don't need more space and I don't have to sell old ones to make room. Win win.