A wireless electronic commerce system (10) comprising a wireless gateway (18) to a wireless network (19) with which a wireless device (11) having a unique client identifier (ID) is capable of communicating. A server (15) or servers (15 and 16) is/are coupleable to the wireless gateway, delivering content items (e.g. software products) to the wireless device (11) and maintaining digital content certificates for content items and digital license certificates for licenses for the content items. The server maintains, for each wireless client associated with the system, a record of licenses for that client and a record of content items associated with each license.