The authors first specify the terms and conditions for the commercialization of intangible goods, and particularly digital documents, defining a mapping between the commercialization terms of the tangible goods (printed information) to the commercialization terms of the intangible goods (digital document). The meaning and limits of purchasing, accessing, redistributing, copying, preserving user anonymity, etc., are defined in accordance with the well established rules governing the trade of printed information. We next specify the requirements that a digital commercialization system of intangible goods should fulfill in order to guarantee the rights of its users (providers and consumers) like user anonymity, superdistribution, marketing policies, etc. Finally we give a brief presentation of a framework and a pilot application that we designed and implemented for the commercialization of digital documents.