Authenticated propagation of adverts to multiple mobile recipient devices, each having both wireless and mobile telephony capability, employs message generation platforms each having a content creation engine, a metadata inserter and a signature generator, for the wireless broadcast of the generated messages. A client application on each recipient device controls viewing of the message, with authentication being provided through mobile telephony communication with a trusted authority which is in turn in secure communication with the message generation platform to hold signature information. According to an incentive policy, a device may wirelessly re-broadcast any message.