A shared SSL will be by your hosting company and the difference that can be noticed would be that the URL will change when the customers enters a secure area of your website and will include the domain name of the hosting company. This may cause your customers to purchase from another, more trusted website as per their thinking. The only way to avoid this is to obtain your own SSL certificate. Wide ranges of products are available to cater to the private SSL Certificate need for ecommerce to enterprise SSL solutions. My cousin had secured the services for SSL Star for his
SSL solutions.