Onur Cobanli explains:
Good design requires more marketing effort then great design and is less profitable therefore; the idea is that the better the design, the higher the conversation rate for any marketing campaign; when you show a good design to x number of people, y number of people will buy it, and when you show a great design to x number of people z number of people will buy it, z > y will hold true; you spent the same marketing bucks but you get more ROI with better design; if you are creating a consumer good which you aim to sell millions, and market for tens of millions, then you better focus heavily on your initial design; because later it will be much easy to market these better designs, and also the better the design the more demand, with an accelerating way; a little increment in design value will lead to a greater value in perceived quality and will most likely result in higher sales.