This console gen is marked by the big push digital sales got, garnering investments from both manufacturers and developers. If last gen digital distribution was mainly used for indie and smaller titles, and the main releases in digital form only coming much later, this gen digital is everywhere, There's no game that releases for both ps4/x1 that isn't also getting a digital release day 1. Speaking about me, nowadays I'm buying almost exclusively digital titles. I'm still waiting to buy a ps4, but the newer titles i got on my ps3 were all through PSN and Steam for my PC.
The tendency is at some point digital sales are going to overtake physical sales on consoles just like already happened in PC, we aren't very far away to see it happening for some big title first, and I would bet Gran Turismo Sports will be a first case.
