Have you ever Googled a product you were interested in purchasing? You may have found the information you needed on the manufacturers website and then searched for a local retailer to see the product in person. Or maybe you continued on the internet for more information, maybe a better price?
When you looked for the information and product did any website design persuade you to make a purchase simply due to that web design itself?
Chances are no. Customers searching on the web are looking for information---clear, concise, searchable, and if they find that information they need a way to return to that information later. Good web design does all these things well.
Sure an attractive, eye pleasing interface is helpful. But web design should be about the product, not the design. First time web planners and small business owners often love to add a bit of flash to their websites. A cartoon character moving around the screen can be entertaining, but unless your product is graphic animations you are better off using your space to highlight better pictures and explanations of your own product.
In the long run, the mechanics of the site---navigation, search boxes, and information are why that customer is there. And giving the customer what he or she wants, as fast, efficiently, and professionally as you can is the only way to provide good customer service---whether in the physical or virtual worlds.