Methods and systems provide information products relating to past, present and future advertising transactions (i.e., contracts to place advertisements in various media) to enable a marketplace in advertising products. Information regarding a plurality of advertising transactions are gathered. Data is analyzed to determine its attributes. Some attribute values are transformed and the attribute values are stored in a database. Attributes are organized or indexed according to a taxonomy of attributes to provide indexes to advertising transaction records. Indexes and benchmarks for various selected types of advertising transactions can be generated by selecting certain records from the database and aggregating the data or otherwise synthesizing information products, such as benchmarks and market entities for the selected types of advertising transactions. Information products may be published and syndicated as market indexes and benchmarks.