I'm not sure this really is 'efficiency', or at least it is 'active user efficiency' rather than 'store efficiency'. I would think of (store) 'efficiency' as t

I'm not sure this really is 'efficiency', or at least it is 'active user efficiency' rather than 'store efficiency'. I would think of (store) 'efficiency' as the amount of money made by the developer for the same purchase on each platform. This on the other hand is "revenue generated per active user", which really will say more about how many purchases the average user makes than anything else.