A method for notifying a licensor of the use of a licensed product at at least one licensee's site, the method comprising the steps of:
- generating datagrams at regular time intervals from at least one licensee's site with a device using said licensed product;
- including in each of said datagrams an address of said licensee on a communications facility, said address being designated by said communications facility without any data being provided by said licensee;
- and
- sending said datagrams including said address from said licensee's site over said communications facility to a licensor's site at regular time intervals while said licensed product is in use.