I think that's not contradicting OP's point. It's a "long tail" type of problem--nobody's going to buy a Super Bowl ad for Uber for model train assembly. Not ev

I think that's not contradicting OP's point. It's a "long tail" type of problem--nobody's going to buy a Super Bowl ad for Uber for model train assembly. Not even every model train buyer wants it. (Incidentally, I can think of plenty of situations where you would give a child a model train and not be willing or able to assemble it and still have it be a net gain for the kid).