e-commerce… probably the biggest single cause of the internet Boom or Bust ideology that ultimately led to the demise of many of the "bigger and better" e-commerce websites.

Custom coded product and content Databases, custom coded display and content management, and strong design, allows your products to be displayed how they look best, not how a 3rd party products thinks that's how products should be displayed.

Strong interface design and understanding or interactivity and usability have to combine to produce a website that not only "looks" like what your target audience wants, but also "behaves" how the target audience wants. There is nothing more off-putting to a beginner than an overly complex website, but there's also nothing more frustrating for an experienced user than a site than lacks advanced functionality…

Integration with current order processing, sales, and marketing systems makes sites much less manpower intensive.. if order's can be handled automatically then less time is needed to fulfil those orders.

shop.dudeskin.com is an example of a shopping cart driven e-commerce website running from a Content Management Controlled database of current products.  An E-commerce website has low overheads, allows targeted advertising and promotion.

An e-commerce website may make a company rich, but is much more likely to add a valuable extra income source.