"You’re probably thinking that most of the non-played games were free-to-play titles..."
Well, actually, no. If I ever want a free-to-play title, I'll download it when I want it. But if I get the chance to buy a game for a couple of dollars/euro's which would normally cost 10, 20 or more, I just might do it - even if I have no interest in playing it right away. To download a free-to-play title and then NOT playing it, would be stupid. (Maybe the bargain hunting as well, but it makes at least a little sense.)