A cross-promotion system that controls promotion between video game makers in an online video game community is described. A first quantity of exposure of the image pickup device is determined such that a maximum value of the output signal from the image pickup device does not exceed a saturation level. A response to the condition may include provision of a perceptible indication that the condition has occurred. In addition to avoiding the need to run a parallel DAS infrastructure, the disclosed arrangements are also useful in shared spectrum environments and other environments where efficient spectrum utilization is desired. The constant voltage unit drops the output DC voltage of the power supply unit and provides the control unit with the dropped output voltage. In addition, the housing has an attachment mechanism for attaching the pump to a venting insert.