This is a method for limiting access to selected features of a freely distributed multimedia file, by disabling selected features of the file (using encryption, compression, or other access denial), distributing the file with some enabled features as an inducement to new users, and offering to enable more features when a new user attempts to use a disabled feature. A licensing system then receives a request from the user's system, identifying a specific operating context and one or more features desired by the corresponding user. Accounting is done and an authorization is sent to the user or the user's system to enable the features. However, the authorization is uniquely associated with the measured operating context of the user and the features remain enabled only for said operating context, thus limiting full operation to authorized users, while permitting new users access to limited operations.