On 1 July 2004 Duncan was appointed chief executive of Channel 4. He took up the job on 19 July 2004. During his time there he oversaw the company's emergence as a genuine multi-platform media business. Channel 4 was first broadcaster in the world to put its entire schedule online with the launch of its 4OD on-demand service in 2006. In addition, Channel 4's share of Total UK TV viewing grew from 10% to 12% and its share of the TV advertising market increased every year to a record 25% in 2009.