A device (100, 200) for playback of video content at a point of user interaction comprising: a display chosen from an LED display or an LCD; a memory device for storing content comprising the video content; a processor configured to controllably output the stored content; an energy harvesting and conditioning circuit comprising an energy storage element and configured to receive ambient radio frequency energy available at the point of user interaction and charge the energy storage element without use of an external AC or DC power source, the energy storage element being configured to supply power to the display, the memory device and the processor to controllably output the stored content; and a substrate on which the display, the memory device, the processor and the energy harvesting and conditioning circuit are mounted, the substrate having a top side from which the display is viewable by a user and a bottom side for mounting the substrate at the point of user interaction; wherein the device (100, 200) is self-reliant for power using only ambient radio frequency energy harvested via the energy harvesting and conditioning circuit; wherein the ambient radio frequency energy is ambient wireless network energy and the energy harvesting and conditioning circuit comprises at least one antenna configured to receive ambient radio frequency signals, a matching circuit, a voltage multiplier; and wherein the video content comprises video segments and characterised in that the processor is configured to output them with pauses and a display of a static image between video segments to conserve stored energy at the device 100 and depending on the rate at which ambient energy is converted by the energy harvesting and conditioning circuit and the rate at which power provided by the energy storage element is consumed during playback. a display chosen from an LED display or an LCD; a memory device for storing content comprising the video content; a processor configured to controllably output the stored content; an energy harvesting and conditioning circuit comprising an energy storage element and configured to receive ambient radio frequency energy available at the point of user interaction and charge the energy storage element without use of an external AC or DC power source, the energy storage element being configured to supply power to the display, the memory device and the processor to controllably output the stored content; and a substrate on which the display, the memory device, the processor and the energy harvesting and conditioning circuit are mounted, the substrate having a top side from which the display is viewable by a user and a bottom side for mounting the substrate at the point of user interaction; wherein the device (100, 200) is self-reliant for power using only ambient radio frequency energy harvested via the energy harvesting and conditioning circuit; wherein the ambient radio frequency energy is ambient wireless network energy and the energy harvesting and conditioning circuit comprises at least one antenna configured to receive ambient radio frequency signals, a matching circuit, a voltage multiplier; and wherein the video content comprises video segments and characterised in that the processor is configured to output them with pauses and a display of a static image between video segments to conserve stored energy at the device 100 and depending on the rate at which ambient energy is converted by the energy harvesting and conditioning circuit and the rate at which power provided by the energy storage element is consumed during playback.