A method and system for subscription-based, entitlement-driven license key generation and distribution for digital goods allows digital goods vendors to manage rights of customers having maintenance contracts or subscriptions. Rights management includes the ability of the vendor to specify upgraded license...http://www.google.de/patents/US7831515?utm_source=gb-gplus-sharePatent US7831515 - Method and system for subscription-based, entitlement-driven license key generation and distribution for digital goods
