An Internet-based, business-to-business web site which aggregates product information from each of a plurality of vendors into a common display format. In response to receiving identification information from an Internet-enabled computing device used by a buyer, the web site displays a list of departments or product categories for which the buyer is authorized to make purchases. Upon receipt of the buyer's selection of a product category or department, the web site displays a list of vendors that have authorized products corresponding to the selected department or category. Upon receipt of the buyer's selection of a vendor, the web site displays that vendor's list of approved products corresponding to the selected department or category. The buyer may place an order for one or more approved products, whereupon the web site receives order parameters, such as the identity of the product and the quantity desired. The web site then forwards the order to the selected vendor for fulfillment, and optionally tracks shipment of the order from the vendor to the buyer. Pursuant to further embodiments, a mechanism is provided for electronically debiting a buyer's bank account in response to at least one of a buyer placing an order and a buyer receiving an order. This mechanism may also be adapted to electronically credit a vendor's bank account in response to at least one of a buyer placing an order from the vendor and the vendor shipping the order to the buyer. Pursuant to an additional embodiment, a mechanism is provided by which data pertaining to a plurality of buyer and/or vendor transactions may be acquired, aggregated, analyzed, and examined.