1. A system configured to reduce volume of transmissions of measurements of affective response, comprising: an interaction analyzer configured to receive a description of an interaction of a user with a media controller that controls progression of presentation of content consumed by the user; the interaction analyzer is further configured to analyze the description in order to identify an action that causes a deviation from a typical progression of presentation of the content; whereby the typical progression is a progression that would have occurred had the action not taken place; a window selector configured to select a window during which the user likely expressed an affective response related to the action; wherein the window is shorter than duration in which the user consumes the content; and a transmitter configured to send a request to a measuring module to transmit measurements of affective response of the user, taken by a sensor, during the window; wherein start of the window precedes time the request is sent.