Sony already does Steam like sales (and free games) for PS+ members anyway. They also do digital distribution of games. All without bolting on annoying restrictions and pages of rules.
"Everyone and their mother complains about how gamestop fucks them on their trade ins, getting 5$ for their used games." Which is why on PS4, Wii U and current-gen systems you can sell your games on eBay or some other avenue for a better deal. Xbox One only allows approved retailers.
This isn't a messaging problem. There are just no consumer benefits to message. You don't need to be always online or block used games to do digital distribution or provide sales as Sony and Nintendo have proven.