Advertising agency founded 1920 as William B Ziff Company, Chicago, acquiring publishers E C Auld Co in 1923; began publishing magazines in 1926; became Ziff-Davis Publishing Co in 1936; produced magazines 'Popular Aviation', 'Popular Photography' and acquired 'Radio News' and 'Amazing Stories' in 1938; published comic books in 1950s; sold majority of magazines to CBS in 1984; expanded into broadcasting in 1979 following purchase of a number of American regional television stations, but sold off in mid-1980s; 2001 Ziff Davis Media Inc; filed for bankruptcy 2008.