The theory behind marketing using demographics is to:
Perfect.Delivery transcends demographic marketing norms because when using Perfect.Delivery you identify the specific URLs of competitors or complements. Since your ads are shown when these URLs are loaded, the user loading these URLs (by your definition) is a potential customer. In this Perfect.Delivery shows your ads at the exact time and at to the exact potential customer that you want to target. Making Perfect.Delivery a more targeted marketing methodology than marketing using demographics.