This is an excellent article from Smashing Magazine on how well designed, uncluttered, simple ecommerce websites work better and help you increase your profits.
Successful websites should have a clear objective.
Each page should focus on one clear message or function. Extra widgets or unrelated products should be removed.
Website users are becoming more focused on what they want to get out of a website and so websites should make it as easy as possible for their users to achieve rapid, hassle free results.
The article also showcases good examples.
My favourites are:
Apple - This redesign has deservedly won acclaim. It is the epitome in a clean and uncluttered approach to web design. There is a clear focus on each product and unnecessary information is jettisoned.
Bell - Similar to the Apple design; it has a very clean feel and the navigation is a pleasure to use.
Shoeguru - I like the way that the product image are central to the website. Great images are so important at enhancing the user experience.