It's vital to give your customers confidence that their credit card details are safe and secure. If you use an online payment processor (e.g. WorldPay) then you have no need to worry as your customer will be redirected to the card processor's own secure online webpage to enter their details. However if you want to take your customers' card details yourself using EShop it is mandatory to use an https:// connections and an SSL certificate is required. A Trusted Site logo displays your certificate and trusted status on the shop front.