Quote : "If your "high end" online store sets off some Javascript effect every time the user touches something, it might be worth asking why amazon.com doesn't do this. Is it because Bezos doesn't know how to sell online, or because he doesn't have as good programmers as you?" -- Paul Graham.
A sign of amateurish design is too much JavaScript. Too much image. Too much "looks cool" while usability suffers, while the designer and developer refuse to acknowledge it.
Therefore a cool looking site is a demo and marketing material for the developer himself, and not a demo or marketing of your product or sales.