Actually the only experience you can experience is your own, IMO. Reading a tweet is you having an experience involving someone saying something and you interpreting that and maybe imagining what they experienced, but it's different from actually experiencing what they had experienced from their perspective. The cost of experiencing from your perspective is still the same amount of attention, and the "innefficiency" is in not being able to experience more with the same amount of attention, it seems like; but on that; I don't think there is inneficiency or any making up for it, it's just about choosing which kinds of experiences to have (they still happen at the same rate of attention conversion).