I. Introduction
We are currently witnessing a transformation of the audio-visual sector towards a new hybrid TV ecosystem, where broadcast and broadband services coexist [1]. Although TV continues to be the central device for audio-visual media consumption, the proliferation of devices such as mobiles, tablets and laptops together with the supply of Internet capabilities to TV sets, has entailed considerable changes in media production, distribution and consumption [2], [3]. This hybrid ecosystem opens a door to enhancing traditional TV shows towards innovative TV experiences, moulding themselves to the new consumption habits and patterns of the users. TV viewers are no longer focused on a single content source or device. They look for additional content on a second screen related or not to the mainstream media, and they socially interact with friends and the community. Furthermore, users are getting used to a multi-device content access, demanding services at any time and from any device [4]. Consequently, TV set has evolved from a stand-alone device to a multi-platform environment, being complemented by websites, applications, online-video streaming, chat rooms and so on.