A system (100, 200) for granting one or more client devices (120, 130, 140) conditional authorization to operate licensed software, the system comprising: a network interface (160, 260) disposed to receive a license identifier for the software and a device fingerprint that uniquely identifies the client device (110, 120, 130, 220) seeking authorization to operate the software, the device fingerprint identifying one or more of hardware or software components of the client device, any peripheral devices attached to the client device and/or performance characteristics relating thereto including at least one of device type, processor speed and available memory, and wherein the network interface includes a memory holding program instructions operable to: determine whether granting an authorization to the client device to operate the software would exceed a license limit for that instance of the software; send, in response to determining that the license limit would not be exceeded, a first unlock key to the client device; and send, in response to determining that the license limit would be exceeded, both (i) a second unlock key to the client device (110, 120, 130, 220) to extend licensing of that instance of the software to the client device and (ii) ad instructions to display one or more advertisements in connection with the operation of the software at the client device and wherein said ad instructions contain information matched with ad serving parameters assessed supportable at the client device having regard to the device fingerprint and wherein the ad serving parameters correspond to a selected advertisement selected for delivery and the ad instructions are arranged to cause such delivery, to the client device, of the selected advertisement based upon the identified hardware or software components of the client device, the hardware or software components of any peripheral devices attached to the client device to which the selected advertisement is to be delivered and/or performance characteristics relating thereto; and wherein the system includes a processor, in communication with the network interface and the memory, the processor configured to operate the program instructions. a network interface (160, 260) disposed to receive a license identifier for the software and a device fingerprint that uniquely identifies the client device (110, 120, 130, 220) seeking authorization to operate the software, the device fingerprint identifying one or more of hardware or software components of the client device, any peripheral devices attached to the client device and/or performance characteristics relating thereto including at least one of device type, processor speed and available memory, and wherein the network interface includes a memory holding program instructions operable to: determine whether granting an authorization to the client device to operate the software would exceed a license limit for that instance of the software; send, in response to determining that the license limit would not be exceeded, a first unlock key to the client device; and send, in response to determining that the license limit would be exceeded, both (i) a second unlock key to the client device (110, 120, 130, 220) to extend licensing of that instance of the software to the client device and (ii) ad instructions to display one or more advertisements in connection with the operation of the software at the client device and wherein said ad instructions contain information matched with ad serving parameters assessed supportable at the client device having regard to the device fingerprint and wherein the ad serving parameters correspond to a selected advertisement selected for delivery and the ad instructions are arranged to cause such delivery, to the client device, of the selected advertisement based upon the identified hardware or software components of the client device, the hardware or software components of any peripheral devices attached to the client device to which the selected advertisement is to be delivered and/or performance characteristics relating thereto; and wherein the system includes determine whether granting an authorization to the client device to operate the software would exceed a license limit for that instance of the software; send, in response to determining that the license limit would not be exceeded, a first unlock key to the client device; and send, in response to determining that the license limit would be exceeded, both (i) a second unlock key to the client device (110, 120, 130, 220) to extend licensing of that instance of the software to the client device and (ii) ad instructions to display one or more advertisements in connection with the operation of the software at the client device and wherein said ad instructions contain information matched with ad serving parameters assessed supportable at the client device having regard to the device fingerprint and wherein the ad serving parameters correspond to a selected advertisement selected for delivery and the ad instructions are arranged to cause such delivery, to the client device, of the selected advertisement based upon the identified hardware or software components of the client device, the hardware or software components of any peripheral devices attached to the client device to which the selected advertisement is to be delivered and/or performance characteristics relating thereto; and wherein the system includes a processor, in communication with the network interface and the memory, the processor configured to operate the program instructions.