I've bought a single "lifetime" license and it was for Elite: Dangerous. Back in late alpha, you could pay $120 for access to all future expansions and updates. I think this would've been a great deal for anybody who likes E:D, but I ended up not liking it very much and was disappointed with the expansions. I still feel like it was a good deal, if only because I can jump into the game whenever I want to experience what's changed and it's cool flying around with VR and HOTAS for an hour, but I don't think I've gotten very much out of it otherwise.
I don't understand very much the appeal of lifetime licenses from the point of view of the seller. If you believe that your product will be good over time, you should only sell time-limited licenses. Am I missing something?