A system, apparatus, and method are presented for allocating for allocating advertisements for display are provided that include collecting a plurality of advertising spaces, each advertising space having at least one associated advertising space variable; collecting a media inventory, the media inventory comprising a plurality of advertisements, each advertisement having at least one associated advertisement variable; receiving a bid price and a target inventory percentage for each advertisement: receiving a request for an advertisement to be placed at a specified advertising space; identifying advertisements in the media inventory that are qualified to receive an impression at the specified advertising space; creating a qualified advertisement ranking by sorting the qualified advertisements by bid price; selecting advertisements from the qualified advertisement ranking until the sum of target inventory percentages of selected advertisements is equal to or greater than 100 percent; and allocating advertising impressions to the selected advertisements.