A non-transitory computer-readable medium storing program instructions that, when executed by processing circuitry, cause the processing circuitry to perform a method of monitoring usage of an image output device, the method comprising:
- receiving, from the image output device, a first message that includes resource usage information for a job, wherein the job was processed by the image output device for a registered user of the image output device;
- obtaining, based on the received resource usage information for the registered user, a total resource usage of the registered user;
- determining whether the obtained total resource usage of the registered user exceeds a predetermined threshold;
- and
- transmitting a second message over a network to a destination, when it is determined in the determining step that the obtained total resource usage of the registered user exceeds the predetermined threshold.