1 ) A method performed by a computer system comprising the steps of: storing a vendor's list of goods and/or services in a data base accessible by the computer system; establishing an instant message communication channel between a user and the vendor; both user and vendor identified by unique screen names, presenting the list of goods and/or services to the user in response to establishment of the instant message communication channel whereby the user can order selected items from the list of goods and/or services, while concurrently communicating with the vendor; and generating an order identification number in response to each order placed by the user, which order identification number references information from the user's screen name, the vendor's screen name and information generated by the computer system, said order identification number identifying the specific order being processed by said user and used only for that specific order.