I'd liken this to the "washing machine effect" that Hans Rosling explaned in his TED talk [1]. He essentially made the case that the washing machine made a huge difference in the history of the world so parents could spend more time with their kids (among other things) instead of many hours a week just washing clothes. I would say Google Shopping Express has a similar effect for shopping trips where the time spent greatly affects the amount of things an individual can accomplish in a day.