In a bricks-and-mortar store visual merchandising is able to create an emotional engagement with the customer by targeting all senses using fine-tuned visual displays, audio, physical textures and even fragrance. On the internet there is really only one sense to target and that is vision – this is why the online visual merchandiser must strive above all else for photography that is immaculate. (It may be argued that a website could also provide music but this is considered very high on the list of design annoyances and rarely implemented in e-commerce.)
Take a methodical approach when assessing the usability of a website. If you consider specific key areas instead of forming a general impression you will arrive at a more in-depth assessment. Otherwise you risk being blinded by whatever gloss the designer has applied over the top, or by whatever result you want to see.