One of the things that happen in some games is that people accumulate rewards.
I was thinking these rewards could be transferred between games using block chaining (crypto currency style) built by different studios.
I guess the value proposition could be as simple as a migration path from a defunct game, but there would be heaps more. For example..
A studio might want to entice an established player base to try out their game so they give them "credits" for doing so that they can use when they return to their existing favourite game. Of course there would be some sort of commercial agreement between the studios so both get something out of it. Players don't feel that their investment in their favourite game means nothing as well. I could be seen as fair in the general community that a "new" player gets a leg up in a new game simply because they had invested so much in a different one.