Photography designed to sell a product is different from the kind of photograph you would make to simply illustrate a product. Pictures that sell are more concerned with the feelings they produce in the viewer. They should be beautifully lit and seem unconstructed and direct. For instance an advertisement for STP motor oil may not even have the product in the picture... instead you see a formula one racing car. When hiring a photographer to shoot your product, get someone who understands this fine line between appealing and informing, and can work creatively to make your product as desirable as possible.