A system (40) for identifying proximate devices (1,2) comprises at least one correlation server (5) for correlating data received from the devices so as to match two or more of the devices and at least one application server (6) for carrying out an application involving matched devices. The at least one correlation server (5) and the at least one application server (6) are distinct servers so as to provide a greater flexibility and scalability. The devices (1,2) may be mobile consumer devices.