I think that the GUI-related tweaks must be on sites that are done properly and well established. For these guys the customers know what to expect so a change i

I think that the GUI-related tweaks must be on sites that are done properly and well established. For these guys the customers know what to expect so a change in design will be received negatively by people that are used to the old site. Although not in ecommerce, the redesign of the BBC site is like that, people want to cling on to the old site and instinctively don't like the new. In time they adjust or get a touchscreen computer and 'get' the changes and what the redesign is about. Most people are working on sites other than the top ones. With these websites where customers are not regulars, change to the GUI is received differently. Sensible updates to the UX will convert.