The importance of cloud computing and its benefits for public sector has already been recognised by national and supranational organisations. Meanwhile, public service advertising is seen as a powerful tool in the hands of public administrations in raising awareness and changing public behaviour towards a social issue. After introducing the main concepts of cloud computing, this chapter describes an interactive, cloud-enabled platform for public service advertising. During the validation phase, which involved seven European case studies, we learnt not only the benefits for both data producers and consumers coming with the platform, but also helped us identifying the gap between these two sides. In order to bridge this gap we propose a novel, open and collaborative platform for public advertising based on semantic Web technologies for service discovery and message delivery. Enabling technologies of the platform are next identified and, finally, the deployment on hybrid cloud environments is discussed.