A system and method for licensing the use of "plug-in" type software that plays audio, video, and three dimensional content which logs the network address from which content is downloaded and played by the plug-in client software, then sends this information to a billing system maintained by the plug-in software developer. This billing system can then bill the content provider that is associated with the network address based on the number of times the content is played by users of the plug-in software. The system and method can also employ a public key encryption scheme to ensure that the network address information received by the plug-in software is valid and to block the playing of content from content providers that are delinquent in their license payments.