Abstract: Systems and methods for publishers to barter advertisement space inventory and advertisements with other publishers by transmitting an advertisement from a first publisher for display on available advertisement space inventory of a second publisher, where the advertisement is transmitted to the second publisher in exchange for credits of the first publisher previously earned for displaying other advertisements for other publishers. An advertisement and a bid amount are received from a first publisher, and an identification of an available advertisement space inventory is received from a second publisher. The advertisement is matched with the available inventory. A credit amount for the first publisher is deducted based on monitored performance of the advertisement displayed by the second publisher, and a credit amount for the second publisher is added based on the monitored performance of the advertisement displayed by the second publisher.