I saw the same web site. The metal cards are indeed neat, but imagine when you are at a conference networking event and everyone is exchanging cards... What do you do if you have 20-30 metal cards in your hand/pocket? Or how do you imagine bringing 40-50 cards with you? There is also a plastic card that I thought provided more flexibility and design elements you could do. Metal cards are great for some unique promotion for bigger brands, like the example of a Bentley metal card on the site you mentioned, or some fancy salon.