I'd say there are probably quite a few people letting their game run while they are waiting for their tokens to refill, thus making the global average time bigger.When is Harada going to lead production on an Im@s fighting game? :3
OK, serious question: How much of the game are you willing to change, in order to either keep the game fresh for dedicated players or to try to pick up new players (or previous players who dropped the series at some point)?
(There's a hint toward this in Tekken Revolution, with the changes to movement and how okizeme works, along with the invincible moves, but is that the extent of it? Will you ever try something as radical as what happened with TTT1 to Tekken 4 now?)
Here's the thing: I don't know how that low percentage (and I'm not questioning that statistic -- that's something I've seen reported in multiple places) with the average session time. There's no way that a free player is going to be playing for 2+ hours at time, it's possible but that leads to a lot of waiting in-game. Granted, they may log off and come back in a couple of hours, but you're not going to run up 2+ hours of game time in a day doing that. It's possible that I am completely misinterpreting that statistic -- do they mean continuous time in-game, or just time played per day, or something else?
The other issue I would have is that the playerbase does not stay even over time. It hit a million downloads fairly quickly, and took about 6 months to hit its current number (which Harada clarified as being 2.8 million on Twitter).
That's exactly what I used to do when I was grinding JoJo ASB's campaign mode: I would let my ps3 on while watching the tv or play on my PC or whatever while my energy would refill.