Retail Sale Via Mail Order Houses Or Via Internet ISIC Code 4791. This class includes retail sale activities via mail order houses or via Internet, i.e. retail sale activities where the buyer makes his choice on the basis of advertisements, catalogs, the information provided on a website, models, or any other means of advertising and places his order by mail, phone or over the Internet (usually through special means provided by a website). The products purchased can be either directly downloaded from the Internet or physically delivered to the customer, this class includes retail sale of any kind of product by mail order, retail sale of any kind of product over the Internet, direct sale via television, radio, and telephone, internet retail auctions.