Progress is driven by competition, and the appearance of your site and presentation of your product can be vital parts of what makes a buyer decide on your product. Your whole corporate identity plays into this, with companies that have an interesting, holistic, and memorable corporate identity performing better than those who don't.
Human psychology draws us to the beautiful, and today's buyers are spoiled by this thanks to the range of stores available and the quality of web design. In this competitive world you need to use everything at your disposal to stay ahead of your competition. A high-quality corporate identity is one of your most powerful tools in this fight.