The growth of attribution modelling is helping advertisers better understand how different consumer touch points throughout a campaign contribute to driving a purchase. But while for a long time attribution modelling was a ‘black box science’, this is no longer the case as machine learning and AI improve, and as new companies enter the space says Simon Thomas, global director of audiences at GroupM. In this interview Thomas also discusses how the effectiveness of online video compared to TV, and what digital measurement is lacking today. Filmed at New Video Frontiers 2018 in London.