On a marketplace, classic intermediaries based on products become less profitable, but infomediary, an intermediary based on information, plays a new important role. To intermediate meaningful and timely information among participants, it has to maintain a data warehouse with an information asset based on a new attribute, which is metadata of physical transaction, as an alternative of conventional attribute on relational data model. The metadata aggregates the raw transactions more pertinently than current attribute, and the corresponding information asset serves substantially for decision making. In this paper, we describe the constitution of metadata on primary product market and the value of multidimensional information asset for market participants. The application shows that each participant can increase its profit by using the information asset, and so can the infomediary by vending it.