Displaying personalized content to content observers by content providers (e.g., advertisers) who disseminate content over a network is disclosed. In particular, enabling the display of targeted content to television viewers is disclosed. Identification of the content observer(s) observing a content display device at a particular time (and/or identification of the content display site) is made, and targeted content for display is selected based on a determination of content appropriate for display to those content observer(s) in accordance with a criterion based on the identity and/or a characteristic of the content observer(s) (and/or the content display site). The attention of each content observer can be sold to the content provider that places the highest value on that content observer's attention. In particular, the value paid by content providers over time can be maximized.