1. A method for managing advertisement opportunities in a network environment, the method comprising: retrieving advertisement parameters supplied by an advertiser; creating an advertisement characterization vector based on the retrieved advertisement parameters; dividing a program stream into a plurality of program sub-streams; dividing avails that are positioned within the program stream into a plurality of subavails that each correspond to one or more program sub-streams; retrieving subscriber characteristics related to viewers of the at least one program sub-stream; creating a subscriber characterization vector based on the retrieved subscriber characteristics; and correlating the advertisement characterization vector with the subscriber characterization vector to determine which subavail is the optimum subavail to schedule a particular advertisement to display.