While the idea of "switching skins" may sound appealing, I question its real value in the ecommerce environment. To me, it offers an unnecessary "distraction" and the risk is that it shifts the visitor's focus onto "trinkets", while we really want them to be focusing on the purchase process. Jacob Nielsen has been researching User Behaviour for well on 15 years (some of you may be familiar with his "F-Pattern" experiments) and Nielsen has stated many times that the more "conventional" the visual logic and navigational hierarchy of a site, the more likely it will be that visitors will stay on it.

Research by Apple (the IT company, not the fruit ) has also shown that visual "surprises" not only confuse people, but cause them to be wary. People develop a "brand awareness" that is critical to things like confidence, shopper loyalty, eyeball retention, etc...

If you start showing off by trying to "entertain" your visitors - rather than help them find and buy what they need - they will quickly navigate away from your site to one that makes them feel more at ease.