Abstract: A device and method for timing advertisement breaks in video-on-demand applications based on viewer attention level includes a video device configured to display video content and receive biometric data indicative of the attention level of a viewer. The video device may notify a video-on-demand server that the attention level of the viewer has exceeded a threshold. In response to the notification, the video-on-demand server may determine a time to display advertisement content on the video device. The advertisement break time may be determined in relation to the video content. The advertisement content may be selected based on the video content. The video device may determine the viewer attention level during playback of the advertisement content and pause playback if the viewer attention level falls below the threshold.