2Setting your PS4 as your friend’s primary PS4
To recap: Anyone can play your digital games on your primary PS4. You can play your digital games on anyone’s PS4 as long as you’re logged into your PSN profile.
Which means you can set your PS4 as your friend’s primary PS4, and set his PS4 as your primary. You’ll be able to play your friend’s games on your system (since it’s activated as “their” primary), and if you stay logged into your PSN profile, you can play any games you own as well. Same goes for your friend on their system. Voila. Game sharing.
Let’s say your friend owns a digital copy of Call of Duty: Fill-in-the-Blank Warfare. Using this trick, you can both play that one copy of CoD:FitBW at the same time. Heck, you can even play multiplayer together, even though you’re a freeloader who doesn’t actually own the game.
This is how my friend and I work things out. When a new game comes out that we both want to share, one of us buys the digital copy and the other sends half the game’s cost via e-transfer to whoever paid the full price. Now we both have access to the game.