The paper sets out the evolution and impact of a new cross media metric, Audience Value, which has been designed, trialled and developed by the BBC during the past 18 months, and which is now being introduced across the business. The BBC serves the UK population across television, radio, online and new content delivery platforms. By measuring consumption and engagement with content across all broadcast media from a single sample source, the BBC is able to gain new insight about how the UK's many audiences respond to different media content, beyond the understanding gained from traditional measurement of exposure to individual media, and beyond simple demographic analysis of audience behaviour. Using this information to segment the audience revealed fascinating patterns of cross media consumption and appreciation of BBC content, as well as the broader content and platforms most valued by different audiences. The paper describes the innovative methodology of both data collection and calculation of Audience Value, and presents some of the findings gained from the analysis as well as an insight into how this ongoing study is helping to shape BBC content on every platform.