Providing shopping assistance in the nature of facilitating transactions between buyers and sellers through research and shopping on behalf of potential consumers for availability of merchandise, through providing buyers with information about sellers' goods and/or services, through promoting subscribing retailers` merchandise, through matching potential consumers to subscribing retailers, and through marketing and advertising to potential consumers on behalf of subscribing retailers by notifying a potential consumer that a desired product is available at a subscribing retailer`s establishment; providing a computerized database relating to shopping for consumer goods; cooperative advertising and marketing of professional shopping services