Tesla's goal is to accelerate the advent of sustainable transport. They want (a) to see as many electric cars on the road as fast as possible and (b) make a lot of money.
B is required to perfect the product -- which serves A better than anything else.
I think the 'Apple way' is most efficient: selling the whole package and making it so good, that people happily pay a lot.
I'm not sure how cars will ever constitute "sustainable transport". Less unsustainable than carbon fuelled cars, maybe. And that's a big maybe, given batteries, power generation etc.
But I suppose there's not that much money in trying to sell bicycles...
B is required to perfect the product -- which serves A better than anything else.
I think the 'Apple way' is most efficient: selling the whole package and making it so good, that people happily pay a lot.