A billboard which is formed as a dasher board (600) and adapted for use in a video content replacement system (400) is described. The dasher board (600) comprises at least one non-visible radiation source (604) arranged to emit non-visible radiation toward a light guide plate (602). The light guide plate (602) is arranged to distribute the non-visible radiation over the light guide plate (602) and radiate the non-visible radiation away from the dasher board (600). An area of the light guide plate (602) over which non-visible light is distributed from is correlated to an area of the dasher board (600) which is to be replaced in the video content replacement system (400). There is also described is a billboard (700) similarly adapted for use in a video content replacement system (400) and which comprises an electronic display, as well as a method of retrofitting an existing billboard (10) ready for use in a video content replacement system (400).