1. A computerized system for providing inventory information in response to a query having demographic criteria, comprising: an advertisement database for maintaining advertising inventory information; a contract database for maintaining contract information; and a server in communication with said advertisement database and said contract database, said server operable to: receive a query having demographic criteria from a user, determine, in response to said receiving of said query, a total query inventory from said advertisement database which satisfies said demographic criteria of said query; determine a total contract inventory which satisfies criteria of a contract; determine an intersection between said total query inventory and said total contract inventory; determine a contract delivery target pursuant to said contract; determine a total sold inventory based on said intersection and said contract delivery target; determine a total available inventory using said total query inventory and said total sold inventory, and provide said total available inventory to said user.