Methods, systems, and articles of manufacture consistent with the present invention provide an electronic marketplace that matches units of content from secondary content providers with suitable vacancies from primary content providers. Vacancies may constitute, or be included in, any digital transmission containers, such as a television or radio programming, web pages, and the like. Specifically, the electronic marketplace automatically matches content offered by secondary content providers with vacancies offered by primary content providers thus filling the vacancies in these containers through a real-time content trading, placement, and distribution system. To do so, attributes associated with the vacancies and with units of secondary content are used to trade and match suitable vacancies with suitable content. This invention enables both secondary content owners and vacancy owners (primary content providers) to obtain the full commercial benefit of their secondary content and containers.