Abstract: An online advertising system evaluates advertising opportunities for online advertising publishers. The online advertising system tracks online users via various tracking methods to receive advertising data and user information for the online users. The online advertising system identifies and segments the online users based on segmenting criteria that are associated with some interest topics (e.g., demographical information). The system calculates projected advertising revenue for each audience segment and generates an inventory optimization dashboard based on the calculated revenue. The inventory optimization dashboard helps the advertising publishers better understand the online advertising traffic and better optimize their advertising inventory. For example, the advertising publishers may advertise to specific audience segments which tend to purchase the advertised products or services.